True value of iridium

[Cptldsilver]

I've been really into min maxing for awhile and I've also watched a lot of the prominent min maxers. One thing that everyone is getting wrong is the real value of iridium farmed in the skull cavern.

The common assumption is 270 gold/ore. This is based on the sell price of an iridium bar (1500/5) with the blacksmith perk as well as subtracting coal bought from clints in year 1 (150/5).

Here's my problem with this calculation, smelting iridium bars takes time. Not the time for the furnace to finish but the time it takes to click the furnace to start smelting and the time it takes to pick the finished bar up.

Let's go through an example. Let's say you can load and unload 3000 furnaces a day if all you do is that one activity. Let's further say you have enough furnaces to do this in one continuous activity without stopping. You are also able to gather 1500 iridium in an average skull cavern dive. That means every skull cavern day equates to about 300 bars.

Therefore, if you go to the skull cavern for 10 days straight you will have 15,000 iridium ore and enough iridium ore to smelt 3000 bars, which you can do in an exactly one day.

Here's the part that people miss. The true value of iridium needs to factor in the time it takes the farmer to smelt it all. To factor this in you have to divide (the number of days it takes you to mine enough iridium to fill an entire day with smelting, N*) by (N+1). You then multiply this fraction by 270. In our example this would look like

10/11=.91
.91×270=245.45

So the real value of iridium in this case about 245 gold/ore.

The interesting thing about this formula is that it will change based on how fast you can mine ore and smelt bars. If you can mine twice as fast but smelt at the same speed then ore is worth only 225.

One other factor is that you can sometimes smelt for "free" by having a line of furnaces on what would otherwise be normal pathing for your farmer. Most commonly this is the path from the desert warp location and the entrance to skull cavern.

 

[One More Day]

Your numbers are superficially attractive, but ultimately, I'd argue that they're wrong.

If the ore is never smelted, then each piece of ore is only worth its basic sell price of 100g. If you went mining on that theoretical 11th day, instead of smelting, you'd have a total of 16,500 ore, worth 165,000g, instead of 3,000 bars worth 450,000g.

It doesn't matter whether a day's smelting will process ore from 1 day, 10 days or 100 days in Skull Cavern, you're not losing value by taking time out to smelt it, because it needs to be done at some point.

They're worth (bar price - coal cost)/5, and that means they're actually worth slightly more than 270g each, because you will collect some coal while mining, so average coal cost is <150g per bar.

Smelting time definitely reduces the g/hr from Skull dives, but not the value of the ore itself


EDIT: I suppose you should also account for the cost of consumables while mining, such as explosives, food, coffee, and staircases, which will bring it back down again, probably to something like maybe 200g per ore, although that'll be different for everyone depending on how much of them you use.

 

[Cptldsilver]

"It doesn't matter whether a day's smelting will process ore from 1 day, 10 days or 100 days in Skull Cavern, you're not losing value by taking time out to smelt it, because it needs to be done at some point"

This would be true if time didn't have any value. Think of it this way, if there's an activity where you can mine something that gives you 1450 gold per bar, you can mine this substance under similar circumstances, it also takes 1 coal per 5 ore, and the only difference being that you could instantly convert all your ore to bars without loading furnaces. In this scenario you should always take the 1450 ore vs the 1500 from iridium.

Yeah the other costs and benefits from skull cavern are much harder to calculate. Positives are
1. Gems
2. Gold, copper, iron ore
3. Coal
4. Prismatic shards
5. Food buffs
6. Monster loot
7. Treasure rooms
8. Other stuff
Negatives are
1. Staircases
2. Explosive ammo
3. Food consumed
4. Bombs used

 

[One More Day]

This would be true if time didn't have any value. Think of it this way, if there's an activity where you can mine something that gives you 1450 gold per bar, you can mine this substance under similar circumstances, it also takes 1 coal per 5 ore, and the only difference being that you could instantly convert all your ore to bars without loading furnaces. In this scenario you should always take the 1450 ore vs the 1500 from iridium.

Yes, Time does have value, which is why it is reasonable to posit that the necessary time taken to load and unload furnaces, to smelt the iridium ore, erodes the hourly value of the Skull Cavern dives, as it is a necessary part of the process of realising the full value of your haul. And as everyone will acquire ore, and use consumables, at their own rates, everyone will have a different hourly value for skull cavern. But it doesn't change the value of the iridium itself; that is very firmly fixed at 100g for ore and 1,500g for a bar, as modified by the tangible costs of consumables spent acquiring it.

Yeah the other costs and benefits from skull cavern are much harder to calculate. Positives are
1. Gems
2. Gold, copper, iron ore
3. Coal
4. Prismatic shards
5. Food buffs
6. Monster loot
7. Treasure rooms
8. Other stuff
Negatives are
1. Staircases
2. Explosive ammo
3. Food consumed
4. Bombs used

I have done absolutely no analysis on this, but I would guess that the sellable value of other stuff is massively outweighed by the costs of consumables.

1) Gems are both rare and not worth much. The only valuable one is diamond, which is traded for triple coffee anyway. Then the rubies are traded for spicy eel, and the jade for staircases. There is a tiny value in the others, but not much, and topaz and amethyst are often dropped when the slot is required for something more important, which only leaves emerald and maybe aquamarine.
2) Other ore all gets reused, either for crafting explosives or for more furnaces. Copper and iron will also both go into crafting kegs, if you're doing those elsewhere on your farm
3) Coal is used for smelting; at best it's a small offset against the spend at Clint's
4) Shards are the only thing of real value that you'll get in decent quantities
5) Food buffs have no sellable value, and they're acquired from a food consumable, which is a cost
6) Most of the time, monster loot is not even worth taking out, as it occupies valuable inventory space. Only the iridium ore drops from bats and crabs are really worth anything significant
7) In the long run, treasure rooms are worth nothing. They can only appear once per floor per save, after that they're empty, and eventually those empty rooms dominate everything else
8) Not sure there is much other stuff. Weapons/boots aren't worth keeping, as they block out a slot each. Stone is recycled into furnaces and staircases. I really can't think of anything else at all

 

[Cptldsilver]

I'm using this analysis to compare one activity to another. So it makes sense to reduce the value of an activity based on the time taken. Your right it doesn't actually reduce the sell price. But most people never think about what it costs to smelt all that iridium. My analysis is an attempt to place a cost on that time.
Most of the other points you make are spot on with a few exceptions.
1. Ore is very valuable if you are in a position where you would otherwise buy that ore from clints. You can make a lot just from cost savings from gathering basic ores. If you're not buying its not that valuable though.
2. On food buffs I'm thinking energy tonic, life elixir, crab cakes, spicy eel. I usually end up getting more from monster drops/treasure rooms than I can use. I usually sell the excess.
3. Monster drops, I'd argue, are very valuable based on the monster. Batteries, solar essence, void essence (for mega bombs), life elixir, energy tonic, crab cakes, spicy eel, omni geodes, cloth are all valuable items. It's not always worth it to take the time to slay monsters but if you do their is some nice drops.
4. Treasure rooms can very valuable, especially early on. Rain totems, crystalariums, iridium bars, slime eggs, and others are all high value items to get. Treasure rooms don't go empty after opening them, unless you're talking about the regular mines. They randomly spawn on every skull cavern trip based on luck when entering a new room with a fresh treasure chest. They can't spawn before level 11 and theirs always a guaranteed chest on level 100 unless you get the iridium milk cutscene.