The reasoning behind the rule is simple. Pricing a used product is subjective. If we didnt have the rule, someone could claim any price is too high. It would be akin to you standing outside the front door of your local pawn shop, telling customers who walk in that the prices there are too high. No business would allow that, and neither should people here selling their stuff. Even online sales places like
ebay and CL dont allow random people to make comments on the ad, the product, or the price. So I find it ironic that you feel its unfair we dont allow it here either.
If we allowed people to openly question pricing here, we mods would have to become 'price cops', and nobody wants that. So the obvious solution is, no commenting on a person's price. Simple. No subjectivity to the rules, they are cut and dry.
If you think the seller just needs to be educated, you are free to PM him and discuss it. Otherwise, consider it a situation where you voice your opinion on pricing by not buying the item. No other expression of your personal opinion on someone elses price, for their own equipment, is necessary or even wanted.
I moved this thread to the proper sub-forum. It is not a general audio topic.