Are we talking a "real" truck you drive, or an RC truck? Do you know what type of class/level of truck you want to build? What type of resources are you looking to spend on the truck? Depending on the class of vehicle will directly affect the cost. I have worked on Late Model stock cars and would bet that the cost of a truck wouldn't be far behind. I'd expect to see dollars in the range of $40K-$60K for something you can compete with.
Am I way off base or was that the info you were looking for?