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> You've taken all the feats
15 feats to choose, but not all of them can be crafting stuff unfortunately. Call it Extraordinary Artisan, Exceptional Artisan, Legendary Artisan, Magical Artisan applied to the previous three feats, Apprentice (Craftsman). That's about half my feats.
> Homunculus crafters
These guys don't actually speed up the crafting process per se. It's more like how I could spend 20 minutes carefully frying chicken by hand, vs popping some frozen fried chicken into the oven for 20 minutes; I receive fried chicken in the same amount of time, it's just in one of those scenarios I could go adventuring while my chicken is cooking. I can still only be working on one magic item at a time. If I had an army of them, they could crank out mundane items really quickly, but magic ones wouldn't get produced any faster than if I were sitting in the forge all day myself.
> making super high Craft checks
This doesn't actually speed up the crafting process for magic items. For mundane items, your crafting check determines the speed at which you finish, but for magic items all that matters is the market price and your time cost ratio from feats and stuff. Hypothetically if the DM made me have to provide the base item first (say, a scarf, or a suit of full plate), I could choose to buy it, or craft it myself, in which case a high craft check would make that particular part of it go faster - maybe a lot faster. For example, if I'm making a set of full plate, I have to make 15000 points worth of progress.
If I have +8, then I make 324 points of progression per week, and it takes me 46 weeks/2 days/0 hours/35 minutes/6 rounds to finish (where a day is 8 hours of crafting).
If I have +80, then I make 8100 points of progress per week, and it takes me 1 week/5 days/7 hours/42 minutes/3 rounds to finish.
If I have +800, then I make 656100 points of progress per week, and it takes me 0 weeks/0 days/1 hour/16 minutes/9 rounds to finish.
But whether it's 46 weeks or 86 minutes or a single round cuz Fabricate, it doesn't matter because that's on top of the time to actually enchant the item in question, which on its own is gonna be sloooooow in a way that Craft checks don't affect.
> etc
If DM agrees that infusions counts for PrCs requiring Arcane Caster Level, I could dip Maester for x0.5 time cost. Since dragon magazine is on the table, I could get a Wand of "Research Aid" (lvl 4 spell from DM 342 pg 58) for another x0.5 time cost. Finally, if I don't craft post-chargen until we're epic, I could take Efficient Crafter (Exceptional Artisan) for x0.1 time cost. Technically, I could also use those "restricted to X/Y/Z" things, but those would also reduce GP/XP so the final effect would essentially be the same amount of time spent making more stuff.
Final costs: normal / triple-restricted
GP = market price x0.253125 / 0.0759375
XP = market price x0.0225 / 0.00675
Time = market price x0.0000140625 / 0.00000421875
Assuming standard treasure, and a 6-man party, we can probably expect to receive about 175000 gp worth of stuff on the way from 20th to 21st level. I could spend that buying 175000 gp worth of other stuff, or I could spend it making 691358 gp worth of other stuff. If I make it myself, then it'll also cost 15555 XP (nearly everything we gained from almost leveling), and take 10 days. Oh and cuz of how XP expenditure works, since this just got us up to 21st lvl I couldn't actually spend all that XP, so I couldn't actually get my full gp value of magic items unless I found a way to bypass the XP cost. If i'm using triple-restricted, I could spend it making 2304526 gp worth of other stuff, which would still cost 15555 XP and take 10 days.
Conclusion
It's just an aspect of epic that's hard to work around unless you're functionally ignoring it. A standard crafter can make 1000 gp worth per day. With all the stuff I've listed here, including the PrC I don't qualify for by RAW, including the epic thing I don't have yet, including those cheesy restrictions, I could craft about 237000 gp worth per day, or about 1.6 million per week. But the restrictions are the least likely to get approved tbh. So probably 71000 gp.
Meanwhile, you know how fast y'all could acquire new items via purchasing? Probably buy literally anything you could afford within minutes, no matter how big that number is. Divination spell to find a merchant, teleport spell to reach the mercant, minutes spent haggling, teleport back. As long as there's someone in the multiverse selling what you're looking for, I'm falling behind. And that 71000 gp, that's basically as high as it can possibly get. It'll be the same limit at lvl 30, or 40, or 100, because I've got all the stuff already.