I think the price is reasonable. I'd pay it. I have a '87 Trek 560 and it's a nice bike. And I could assemble that 420, and most likely, make a profit here in the sf bay area. But I'd keep it to ride.

Btw, I just paid $100 for a Nishiki mixte frame and box of parts, and yours looks in better shape. But to me, that frame and box of parts looks like it's going to be a lot of fun for the money.