550 watts, quality and under 50 bucks... pick 2 or get lucky.
Rosewill Capstone 550w $65 (high quality Super Flower build)
EVGA 750B $49 after rebate, not incl. shipping
- not the best quality but could be much worse (built by FSP)
- also not as energy efficient compared to the Rosewill
- but it's a bit oversized so you don't have to worry about pushing it too far
- 5 year warranty is a huge plus at this price, but Rosewill's 7 year warranty is still better
- I'd expect it to be somewhat noisy, even EVGA's Gold units are a bit noisy
XFX 550W $53 AR
- similar quality to Rosewill, but less efficient and with 5 year warranty
- solid choice, but some people complain about it being noisy (not 100% sure how it compares to Rosewill on this front)
EVGA 600B $35 AR
- worst quality of the bunch (built by HEC) but still works... cost is the only redeeming quality, but with 3 year warranty, it may come back to haunt you
I'd go with the Rosewill...