It's not a TERRIBLE deal as long as you can accept that, before you're done, you may have as much in that top end as it would cost you to buy a fresh new one.
If you get it and it's not been ported, and the current bore is blown, you're going to need to get it ported $150, bored $50, and buy a new piston $110. Before long, you've got a cylinder which has already lost one of it's 3 lives and you're into it for as much as a new vito's kit runs.
If, by chance, it doesn't need boring.... then it's not a terrible deal.