I propose a modification to the Market Boards so players can create market orders similar to stock trading. The buy side should be able to set a quantity and price for an item they want to buy and then a time option to specify how long to keep the order. A checkbox will allow partial filling of the order. The order will remain open until the quantity and price requirements are met, at which the transaction is made. Limit the number of orders to prevent market failure. The sell side already works as intended but there should be two tabs on the market sheet, one for items for sale like how it is, and one for buy orders. A new button on the pricing window will be called Liquidate, which will fill the highest priced orders.

As for repairs and melding, that could work, but in the end, you'll just have bots camping that area for gil. You have to restrict the number of times per day a person can perform repairs/melds through that system.