A good concept to the buy / sell price is that any POBs that store mined ores wont get miners dropping ore off at the price for selling to the traders and then means that the POB makes more profit and does not lose profit.
And also for any POBs that sell equipment it means the prices can be adjusted accordingly and also some people may decide that they can buy equipment from people and advertise it and do another service that way and it would mean that people could sell their unwanted equipment to them instead of advertising on the forum, IF they want to.
I have been a POB owner for along time in this game and this idea opens up options for people who wish to use the function, and basically all you need to do is set the BUY and SELL price the same if you dont wish to use the function to its best ability ......simple.
And once again, this idea is really good and could improve POB operation.