Re: cracked block ?
Pass on the boat, it really doesn't matter where the block is cracked, unless it was already your boat, an external crack, and you didn't mind j-b welding it or something and hoping to get a few more hours out of it. It could have also cracked an internal wall, in which case it would have water in the oil as well.
Depending on the boat, you will be spending a good chunk of change on a new block and most likely will find a bunch of other stuff as you swap that will eat into your wallet. There are simply too many boats out there in this environment for you to get into something that might totally turn you off from boating for the future.
