A server-side trading house would take lots of effort to implement but a player-run one can be cheap using back-end tools realmeye already has.
System
Each player submits:
- email and password of one mule
- a set of offers with the mule carrying items to be sold
Realmeye:
- match buyer and seller offers
- automatically trade on their mules
Consideration:
- trade done on mules because can’t login the main when player is on and less risk in case of a password leak
- initially only open to red star or above to prevent players flooding the system with offers from their mules
- with 50k players and at most 8 offers from each the system would support 400k offers. Seems manageable with moderate server cost
- ask Deca to whitelist realmeye IP; too many logins from a single IP can be incorrectly treated as an attack