You might end up having to spend a lot of money getting that engine (and the rest of the sled) all running again. It kinda comes down to if you'd be able to do all the work yourself, how much the parts would cost, and then most importantly... how much the sled would it be worth when all running again?
My advice is to find out what year and model that sled is, then do a google search for all simalar models curently for sale to get a rough idea what it might be worth if running. To preform this research all you'd need to do is type in the search term for sale and then the sleds year brand and model.
You could also try doing a couple more google searches by starting out the search terms with replace rod bearing and for sale carburetors. Hopefully these searches would direct you to some good info to help you make your decision to buy it or not.