AMD CPUs likely to drop in price? Specifically the FX 8350

The "CX" line uses some inferior Samxon capacitors that do not like heat. I would not use one in a gamer, as they've been known to fail early. A 550W-600W Seasonic, XFX, or Rosewill Capstone would be better.
I would not gamble on price drops. Too much is going on with various national economies, and the global economy, to bet on drops.
If you want to save some money, get the FX-8320, which should OC to the same levels. Make sure your motherboard can handle the later FX models, and has decent VRMs (with heatsinks).
 
I would say that you would be okay if you bought it now because the "replacement" wouldn't be coming out for a while. If you are looking to save some money, this CPU occasionally goes on sale at Newegg.com with promo codes.

I would say just get a 600 watt. You will be fine for now and for future upgrades. I would avoid the Corsair CXM 600W PSU's because the CX line tends to be of low quality. This Seasonic PSU has good reviews and is enough for future upgrades.

http://www.amazon.co.uk/Seasonic-S12II-620-ATX12V-Standard-Supply/dp/B003BIEOCI/ref=sr_1_1?ie=UTF8&qid=1400709771&sr=8-1&keywords=SeaSonic+M12II