That heavily prepared deep-dive Skull Cavern strategy is often given as advice here, but bear in mind that it's Year 3 advice since it requires already having plenty of iridium with which to make the crystalariums (i.e. I have found that advice completely unhelpful, since my issue is getting iridium).
On the other hand, I have gotten two prismatic shards and 2-3 dino eggs in my occasional shallow Skull Cavern runs. Not sure if that's abnormally good luck, or about what one would expect.
Also note that you don't have to spend a prismatic shard to do the movie theater bundle. Make a sturgeon pond for the caviar, get your dino egg, and the wine, ancient fruit, and void salmon are easy enough.