It's because BuyDomains and other big players want to buy at wholesale but sell at retail level to end-users.
That maybe true, but when it comes to buying domains at auction (wholesale) their willing to pay MUCH more at auction compared to what they offer to resellers.... That's really what this thread is about.
Many years ago, I won a backorder for a particular domain, I also added it to Namewinner, this was when Namewinner was actively grabbing domains, Anyway, the interface allowed the bidder to increase bids long after the auction ended, I did this to see who had the highest proxy bid, and found out that Buydomains placed a $2000 bid on the domain, so I felt I got a great deal at $60.
Last year, I submitted the same domain to Buydomains along with a list of others, and the offer came back for; (get this)
$75
No kidding.