So if coins are selling for $600, then I could buy 8 for $4,800. What could I hope to make? Where do you think the price is going? Double, Triple or back down to $200. I lost money in the stock market - I don't plan on losing money by buying coins. I don't know why the latest strategy and suggestion is to buy bitcoins? Maybe when you could buy 10,000 for $1 when they first came out as a joke, but not at $600. Sure, it's possible that a coin will be $5,000 a year from now, but I have my doubts.
Just to give you an idea an AntMiner S2 (running at 1TH/s) would yield about 0.3 BTC/day ($23/day). Assuming that difficulty doesn't change (IT WILL!) you'd ROI in roughly 100 days. You won't be able to run an S2 profitably (assuming $0.10/kwh) after network rate hits ~800m. If you have cheaper power (unlikely unless you're on a big commercial plan) you might make it a little longer, say 1.5b GH/s.