Canon 1d mark iin vs. mark iii

[camerabuff]

I'm thinking of getting either a used iin or iii to shoot sports photography and children (who are too young to sit still).  Two questions:  (1) what is the consensus on which of the two is better at autofocus in servo mode, outside?  and (2) what is the going price for a used iin in very good condition, with somewhere in the 20k to 30k range?  (I've seen some used ones advertised in the 1800-2100 range, which does seem rather pricey for a discontinued model; on the other hand, the used iiis seem to start closer to 3000.)

[Bob Atkins]

I can't answer your questions based on personal experience, but if you haven't done so, please read this page (and the links on it) regarding AF and the 1D MkIII

http://www.bobatkins.com/photography/digital/canon_1D3_1Ds3_updates_2009.html

For used prices I'd take a look on eBay and see what they have sold for in completed auctions. That usually gives a pretty good idea of the used market prices.