That’s a Spartan 6 but you really want the larger fabric parts. If you go to Digikey they will quote starting at 20k, but on ebay a few hundred will do assuming you have a Vivado license capable of building a bitstream. It is possible to commandeer a board as in that post but often not worth the time vs just making your own. Rarely prototypes with only the power distribution and JTAG appear. Those are a bit easier. Like this https://www.ebay.com/itm/114784061306?hash=item1ab9a9c77a:g:...