200 W for GPU + 84 W for CPU, adding up mobo, RAMs, fans i guess a quality 500 W PSU will be sufficient to run this rig. Am i right?
Yes can go pretty low on amazon as low as 22ish.
Logisys Corp. 550WNo. Just no. When you mine you put lots of stress on the PSU. A shitty one could fry itself, the mobo, and your gpu. Buy from a quality brand like Antec, Corsair, Seasonic, XFX,cooler master, Or ocz.
In the budget range I recommend the Antec earth watts/earthwatts green series, 80PLUS certified and reliable. You'll need about 450w for that system, plus 15% headroom, a 550w should do nicely