17MH/s with the current difficulty will earn you about BTC$0.01 per day, which is about USD$0.08 per day at current exchange rates.
Here's a good chart of common GPUs:
http://bitminer.info/ You'll get somewhat better MH/s than the chart shows because mining software has improved. Figure an extra 30%.
Here's a profitability calculator you may find helpful:
http://bitcoinx.com/profit/Good luck!