Are you talking about sha256 ASIC? http://www.alloscomp.com/bitcoin/calculator
Yes. Thats a great bitcoin tool, but I know with only 30-50 gh/s bitcoin wouldnt be all that profitable.
I could be wrong, but aren't there a few sha256 alt-currencies out there? I know they're value is really low right now, but would any of them be worth mining with the hope that their value could go up?
Something like this would be profitable in the short term. https://products.butterflylabs.com/homepage-new-products/600-gh-bitcoin-mining-card.html
But it's hard to determine when this will become obsolete. If you play the market right you could make a decent profit. If not you may lose.
You could spend the same amount of money and mine scrypt coins aggressively and sell/trade for bitcoins.