you gotta remember tho mate there aint many m3 evos being sold for spare mate so prices will be a lot more expensive.

http://cgi.ebay.co.uk/M3-Limited-Sli...3A1%7C294%3A50

thats the price of a second hand diff. I personally would have to buy a brand new one mate as you dont know how these parts have been used in the past. That way if you have a brand new diff fited n it goes wrong you got some fall back mate