Oh man, I’m mad I didn’t find this game earlier, just so I could have taken part in this conversation earlier.
GGG massively failed at developing a trade system that was reasonable. It would be okay in a LAN of 4 people together (since that’s how they designed it, to be a game that would fit in in 2001, but not 2019), but it massively fails in every way imaginable at scale. The Trade Manifesto Chris wrote is more of a mockery and a misunderstanding of his players than it is a well-researched explanation of how game markets work.
Please don’t copy their dumpster fire of a system in any way.
Even games from the early 2000s have decent and enjoyable trade systems. I personally enjoy how it’s done in Ragnarok Online (even though it relies on a 3rd party indexer to find items, and even then it can’t handle selling items of over 1 billion zenny–it’s a miracle the game is still alive after so long, much less the economy is still running). I think a fair bit of innovation has to come into play.
On the topic of Legendaries, I think there’s 3 other options: Smart Drops, so only legendaries for your class will drop for you (so you don’t find a Void Knight-focused sword if you’re a Lich); Another is making Legendaries only tradable for other Legendaries, so you can’t RMT to enter the upper echelons of the game instantly; The final I thought about was making Legendaries shatterable to create high-end tradable crafting components. I like upgrading or modifying Legendaries as an idea, we see PoE doing that now with Veiled Mods (except it’s still boring grind-forever RNG gating there).
Cygnus, I think you have the best idea overall. I haven’t seen that done before, or even attempted. It would take a bit of time, and a decent size training data set so your AI could give mods a base value, but I think you could make one hell of a trading AI, especially if you trained it to always win–the bank always wins. It could even act as a 3rd-party in the trade experience, and keep track of how much money it has, and if it gets low, its offers start to dip in response, so it can learn from the negative traits that led it to lose money, and regulate the number of less-desirable items on the market.
Whatever is implemented, just please don’t make it like PoE. I’ve noticed most of the people who posted here that mentioned PoE are SSF, and I don’t think that’s a coincidence (SSF Vegan Crossfitter BTW)