So I guess the 5D Mark II is the better option as the Mark III is too expensive. Also I guess the 5D Mark II is still going to be a popular camera, right?
I'll go for the 5d2 because after a lot of research I think the added features of the 5d3 are not worth stretching my budget - even the latest radio flashes work ok. So for me, it's rather 5d2+2x600rt than just a 5d3 with lighting from my cigarette lighter.
But you really have to ask about specifics, i.e. what you want to shoot, to get good advice on how 5d2/5d3 differ.
It depends what you shoot. If you mainly stick at ISO800 or below, shoot landscapes or macro, for instance, then the 5DII is probably just as good a bet as the 5DIII. In fact, if you use manual focusing a lot, the 5DII may even be a better bet, because the 5DII can take precision focusing screens!
Here in Australia, the price of the 5DII seems to still be drifting slowly lower. Incidentally, I think the 5DII originally started retailing here just over $4000. The 5DIII is currently retailing here for a little under $4000.