Plenty of people do pay 75-80% of retail, especially on CL and eBay. DiaperSwappers, not so much, unless it's one of the beloved brands (that I find aren't necessarily so beloved in other markets). It really just depends on your buying market.
Laura, mom to ds "Big D" (1.09), dd "Azalea" (10.10), and twin girls M and B (3.13)! Wife to my favorite. Cloth diaper industry geek. Birth geek. Church geek.