Which Extender for Canon 70-200

[413x]

About to sell my sigma 120-300mm os

This will leavee very short for my favorite photography (wildlife)

So will need and extender as 400mm do II is out of budget.. sad times

There is a whopping difference in price between mkii and mkiii
Is it worth it?

From what I gather, only the 1.4x is worth getting. The 2x is asking too much

 

[413x]

its the f2.8 mkii
if the mkiii includes AF speed enhancements it will be worth it. as no doubt if i was to get anything longer it would end up on that too

unfortunately 200mm is now my longest lens after i get round to selling the 120-300