It depends on what you're promoting. I've been able to get 2 cent clicks for UK,CA, AUS, and US campaigns. Not for everything, of course.
I know that in my country I cant get below 0.05$ because they use somesort of tax on our country and it is rather annoying.
As suggested i would say its down to what you're promoting, also you need to take all the usual factors into account that could contribute to a lower CPC. Even if it did work that way where a country could have generally lower CPC, it would make no sense to be targetting that country if its not ideal.