Because its their item and they can sell it for what they like, and I'm sure if you were trying to sell and item ie: wheels for $500 and IPfreely comes along and states in your thread oh you can get em off ebay for $350 you wouldnt like it much.
Especially with the demand of PFC's now that apex engineering has ceased production there should be no reason for the price to drop. They are a respected ECU with excellent tunability by numerous tuners Australia wide. If you can see better value in buying a Microtech go buy one, dont spam someones thread by stating how cheap you can other ecu's elsewhere. I, like the user's thread you spammed, would be pissed off too...
End rant...