Because the sellers don't have the opportunity to sell directly to those buyers...
If they did have the chance but didn't then I wouldn't mind, it would then be on the sellers but they have no way to do so.
In the meantime though all the servers prices are very ****d until they make data center MBs linked. I do understand that the higher prices are here to stay on some level but they are inflated right now because markets are beholden to the lowest common denominator (the most crappy low pop server).