You can't really blame them. Buy low, sell high is an age old, well proven methodology.
It's nice when they buy low, sell low as well. I got a 22" 50s A ride from them for $50 last year. Several other good buys, but that one surprised me to see on the wall.
Though they have the audacity to be selling it at twice what they paid me. Ha! Good luck.
That's not "audacity", that's "profit margin". If you think that's bad, there's a popular used music store in Portland who has the policy of buying gear for 1/3 of what they will sticker it at. Of course, they sit on lots of merchandise, but their store is always well-stocked!