That looks to be an oval track race kart, I think I see some track offset front to rear. It's also missing the engine mount, which are sometimes frame specific but almost always expensive. It's also missing almost everything. From the looks of it, he just painted it, so you might ask if he has other parts for it.
Otherwise though, unless you want to do real oval track racing with a BIG budget, I would steer well clear of that! I'm not even sure I would take it if it was free, certainly not $150 in my perspective.
A complete sprint kart frame would be awesome, especially if it's a roller.
