How much is a 1968 hess toy truck worth?

In perfect condition, about $400. If in mint, about $275 dollars. If it is yellowed, virtually nothing in terms of this truck. You could probably only get $30 to $50 dollars for it if everything else including the box are there. If the mirrors are gone and it is yellowed and has no box would be virtually zero dollars. The reason I mentioned the mirrors is because Amerada Hess made them very delicate; unintentionally, of course. Hope this helped!