That is essentially the FPGA value proposition. While they are more expensive than an ASIC because they are re-programmable, you don't have a huge up front investment in masks and wafers. So a decent FPGA set up would probably set you back $10K but you could re-design at will into different sort of 'coin' miners. The book 'Cracking DES'[1] talks about building an array of FPGAs to brute force DES keys. If you are at all interested in ASIC/FPGA based crypto 'mining' you should have and read that book.

[1] http://www.amazon.com/Cracking-Des-Encryption-Research-Polit...

http://www.amazon.com/Cracking-Secrets-Encryption-Research-P...

Deep Crack was big news some ten years ago, but this is just a random link to wikipedia, with no other commentary about why it might be relevant now.

On a related (but just as irrelevant) note, a friend of mine had one of the production-defective CPUs from that machine that she wore on a pendant for several years.