If it's as straightforward as you make it sound (i.e. it's like-for-like but is used & being sold for more than new), I'd post publicly on the forum querying the price and why. Yes buyer beware to an extent, but they seller may not be aware they have priced it too high, and if they are, seller beware, they are posting it on a public forum so if someone wants to point out the high price, it's fair game.