If it doesn't have pitting, the sights are on it and there are no cracks in the stock (look especially in the tang area) I'd try 350 if it's 75%. Maybe 325. All the seller can say is no.
If it's truly 75%, $350 is a more than fair offer, but few folks truly grade their guns at 75% unless they are rough. Let us know if you get it...it sounds like it's certainly worth going after.
