Being able to set a SELL and BUY price is actually a great idea and stops the need for a POB owner to keep stopping the sale of the ores while filling the base and then changing back to being able to sell to traders who buy from the base.
Implementing this would make it much easier than having to change the prices all the time and save administrators who cant always log make the changes and also the comment about money going missing because people sell equipment to pobs to get money (and I have experienced this ) where someone who was making equipment was emptying a pob I had of money by selling the item to one of the bases and it was jump drives so hundreds of millions was being taken by doing that.
I do understand that you can change values within the base to stop this happening but, you cant always keep track of everything specially if you have alot of items list in the base.