I would opt for the Capstone as well - the OEM is a much better one than the CX500 (Super Flower vs. CWT, I believe @shilka ?) and you still have Newegg support on your side (Rosewill is the in-house brand for Newegg).
Today there is also a Shell-Shocker deal where the Rosewill Capstone 550M is $55 AR.
Also, even if you aren't looking for the best, your money goes the farthest and you can be sure about reliability with a Gold-certified unit and a good OEM. You know it won't blow up.