This is old news. FPGAs have been pretty much the standard tool for large-scale cryptanalysis for at least the last decade or so, and in fact can be used for any kind of simple, iterated computation. Anyone who says they have no resale value because they'll be useless if Bitcoin fails or changes algorithms is an idiot who doesn't understand what "field-programmable" means. 
So how does the marketplace for used FPGAs compare to that for used video cards? Is there some repository of working code for the various FPGAs? I ask because the codebase for GPUs is pretty small and specialized.