Cablesaurus.com is our distributor, so that we can focus on working with FPGAs instead of USPS. 
Cablesaurus appears to be doing a terrible job, as the X6500 does not appear to be listed on their website, and the link on fpgamining.com just takes you directly to cablesaurus.com.
Yeah.. Even when the X6500s were listed and showing as 'out of stock' - you couldn't put in a pre-order. They've surely lost out on a few impulse buys that way.