Hauling lumber

Where’s the part about his project is going to be exposed to the elements thus needing to be pressure treated? I’ve never seen anyone buy 100 pressure treated 2x4s, usually for decks it’s 2x6 or 5/4 x 6 nosed etc. He said it would weigh 900-1200 lbs., using 2x4x8’s sounds like a regular lumber load for framing a building of some type to me. OP can weigh (pun intended) in.
My earlier post told him how to evaluate how many he could carry in his truck bed and that is what he asked.