I'm guessing the reason you're asking is because you want to downgrade to save some money, so you'd rather have something well under $90 rather than the best unit under $90 (which may be close to $90)? As for things cheaper than the Earthwatts 650W for $65--a very good deal--let's see...
As long as you keep the GTX 560 overclocks fairly mild and particularly if you don't run things like prime + FurMark, you could maybe go as low as an Antec Earthwatts Green 380W if you want to save money. It's at $35, which is a great deal for something of that quality--though it's definitely not in the same league as a TX650 V2:
Too bad the Enermax NAXN 80+ 500W sold out, since it was selling for $45. It should be CWT DSAII and pretty similar to Corsair CX series:
Rosewill Green Series 530W for $50: