I'd be worried about the cylinder and crank. Hopefully the piston stuck to the cylinder wall before the crank got hurt. Then you just need a new piston (which is a wear item anyway) and maybe a re-bore and re-plate or sleeve (which is worth doing once anyway, as that factory deposited tungsten isn't as good a coating as nicksil).
If its piston and cylinder, you can get everything you need for a premium 225 big bore conversion for about $500, or probably do it on the cheap for $300 or so.
If it's the crank, you will be splitting the cases. Not rocket science, but not trivial either.