1. It doesn't have 350 horses, unless he's modified the engine. Otherwise, he has 245. It's a 350ci engine, but that doesn't mean anything about how much power it has. And the 1988 Corvette is rated at 245horsepower.
2. It's worth around 5-7000, depending on the market. I just looked at Craigslist for my area, and that's what they seem to be going for.