What is, in your opinion, the best miner for me to buy with a $500 budget?
I've already got a small LTC rig and some smaller BTC miners, and I've finally accumulated about 1BTC or $500 worth.
Is there a miner I will achieve ROI with for this price? Anything worth buying at this stage in the 'arms race'?
Lol, you need to check the exchanges more often. BTC is $70 shy of $500 right now. But to answer your question, AntMiner S1 is your only option right now.