Having a few lists from different people should be ok. It gives the Community something to go by.
Everyone needs to do their own research for prices though.
I agree the same people or group posting too often is a bit much and will be monitered and if needs be will have posts removed as duplicates even if 1 or 2 prices have changed. It could easliy be edited into another post instead. Especilly if it's from the same FC.