Need Quick Garage Cost Info ASAP !!

My cousin just ordered a 42 x 36 with a lean too on the side, it was $18K, he had the site work done last year, its on a fairly flat piece of ground, it think that cost him around $1500.
He drives for the local concrete company, so I assume he will receive a discount on the cement.
So I bet he comes out around 30K for a completed structure.