What do you do with your FPGAs as bitcoin mining isn't profitable anymore?
Have you switched to other currencies?
I've sold them to people who are using them for other compute needs. The FPGA boards are still worth something as FPGA boards, and based on eBay this seems to be on the order of ~$150 per 1.15y.
If you have 10 or more with power supplies and USB cables, I will buy them from you for my RSA-1024 factoring challenge.
What are you willing to pay? I know of a few more quad ztex boards for sale (blend of real and clone).