2 tonnes is around 4400lbs so for recovering yourself from mud you'll be needing twice that much pull, at least. 
It'll be good for recovering a boat onto a trailer or pulling you across a carpark but that's about it.  
 You can get a new 5000 or 6000lb winch on Ebay from £40-£60 but the cheapest 8000lb ones are around £250. Then you've got to mount it somewhere.  

J.D. 
You sure you mean 12 tonnnes and not 12,000lb winch? 
12 tonnes is 26,400lb, you don't see many of them on sale!  :shock: 
Although it would pull you out of anything you fancy getting stuck in!!  :lol: