Instead of +1 with each quality increase, maybe 5% for silver, 15% for gold, 25% for iridium for one extra seed?
Less chance for "failed" attempts on top would be nice, too. So that it still increases the chance of getting crop seeds.
If i weren't clear on the first half:
Silver = 5% of getting 4 crop seeds from silver, 15% for gold, 25% for iridium.
Plus less chance for non-crop seeds, including Ancient seeds, as it'll be focused on crop seeds.
Not that you'd really need Ancient seeds from crops if you have Ancient Fruits and a seed maker, but i just wanted to base it on the crops.
Maybe making Luck a factor, so that the given percentages above are lower, but get buffed with Luck.
And Ancient seeds being Luck based would do... would even be nice to have a low Luck day to get crop and mixed seeds mostly XD