Looks like a classic case of someone trying to do a barrel job with the old hammer handle-through-the-frame trick.
This is why I try to tell people NOT to attempt do-it-yourself barrel work without the right tools.
The 3" Cobra is more uncommon, so the barrel should bring fair dollars.
Your best bet is to part it out on Ebay.
Strip EVERYTHING off you can, then sell either as individual pieces, or as a parts kit.
Here a link to Gun Parts, which should give you an idea of what prices to start at for the parts.
Another option is to sell the gun as is on one of the auction sites.
A really, really GOOD gunsmith/welder can repair these cracked frames, so you might find a buyer who'll give you more than parting it out would.