My carport plans

I know there must be something that I'm forgetting. I priced all this lumber at lowes website and it just doesn't seem possible that I can build a 12x50 carport this cheap. If Its true, I can afford to build the other carport as well.

If you want to help buy more shop supplies, you can shop through the links below. It doesn't cost you any more, but I get a small fee when you purchase something at any of the links.
My website https://bcblades.net/
Amazon https://amzn.to/3DqKTaP
Combat Abrasives https://bit.ly/3mFIWRL
Renegade products https://bit.ly/3ssp9Go
Maverick Abrasives https://bit.ly/3kxAyBp
Donate https://www.paypal.com/donate/?business=JAX9BNBWK49PE&no_recurring=0&currency_code=USD