I'd jump all over that deal! Just give it a good checking over before handing over the money and you should be good. I'd do a compression test and see what results you get.
You may get lucky and only have a loose cylinder head or a stripped nut or stud. For the record, its almost impossible to blow the Blaster's stock copper head gasket, but cylinder heads do come loose and leak from time to time. Usually, you'll see oily gunk spilling out from the side with the leak.