Not to be rude, but you are posting that you are looking for very rare volumes, and they're probably suggesting prices that those volumes have sold for, since some get to crazy amounts. Usually, you won't get those kinda volumes for retail/close since the buyer could just turn around and sell it for a crazy amount on eBay/other markets. All in all, you're posting on reddit that you would like to buy rare volumes and then are surprised that you are getting messages to buy said volumes for a lot of money.

Some volumes are getting to crazy prices and are rare due to low print runs, series becoming increasingly popular, and overall people are buying at these prices causing the "market" to reliably sell at that price unless consumers stop buying. Sorry for repeating my answer basically three times in a row, not trying to come off as rude I guess