So the couple of hundred dollars worth of drywall you were refering to in your garage is not the same quantity as the drywall on the truck that you said was only worth a couple of hundred dollars?
Sounds like you need to define wholesale, retail or whatever other classifications of material you are applying. Otherwise your posts would seem to be susceptible of being misleading.
Public Disclosure: If it sounds too good to be true, I probably have it in my portfolio. (Don't make any financial decisions based on my posts. You've been warned)