Not really more expensive at all:
Mobo: Asrock 970 extreme3 - $75
Cooler: Hyper 212 EVO $29
PSU: 600W PC Power & Cooling 80PLUS Bronze (Modular) $59
With the 3470, you're looking at something like:
Mobo: MSI B75MA-P45 - $63
Cooler: Intel Boxed - $0
PSU: 500W PC Power & Cooling 80PLUS Bronze (Modular) - $69.99 (the one you're talking about actually goes for $79.99, and that's after a rebate)
In addition, the Core i5-3470 is slightly cheaper than the FX-8350 ($5 at the moment, woohoo). Overall you save something on the order of $50-60 on the total build.
Anyway, none of this is directly relevant to the OP, who is buying a prebuilt system and outside the US.