Suggestion: Create market board listings to purchase an item - to help fix economy

[Nicobo]

Allow buyers to place "buying" requests for a specific amount and price through their retainers, and sellers to fulfill those requests. (Additional improvement: allow partial fulfillments for both buying and selling?)....

Someone had suggested this idea 2years ago, but he could not tell how to manage the payment.
one example was, the buyer should have prepaid, and what happen if multiple crafters making the requested item and buyer needs to cancel the request..etc? ^^;