The prices are ridiculous in many cases, but the drive of most private enterprise out there is to make a profit, not necessarily to play the charitable paladin.
Whenever I find prices I'm disgusted by (and that's been more often than not lately), I cool my jets by imagining what I would do personally if I had several units of the item in question (lets say BCGs or Pmags). Would I be so generous as to list PMags on GunBroker with a Buy-it-Now price of $14 each or bolt carrier groups at $90, or would I set the reserve at $14 and $90 respectively without a Buy-it-Now option so the highest bid would reflect the current market value?
Once I realize I chose the latter, I ask myself, does that necessarily make me greedy? My answer is typically no.
I use this ethical standard of measure to judge the actions of others (including businesses) who are selling high-demand/non-staple goods.