I posted in another thread about my thoughts on this, I would be for it..Im going to just copy past the post from that thread here to save a rewrite.

{I like the buy order idea also. I think it should add another dimension to the markets without effecting to much the normal MB,if handled correctly. A reverse of the MB maybe, where the buyer pays ahead while placing an order.If the order is filled within a set time, the seller is paid and delivery made. If the order is not filled, then gil refunded. This would allow the buyer to play at the sellers game somewhat,but force those in need of an item right now to go to the MB.

My only thoughts are on how messy it would be to implement and how popular it would be,would it be a ghost town or destroy the MB. Even still a buyer v/s seller game to dominate might be fun.}