If you get the package deal from Carter Lumber, 84 Lumber, etc you are looking at around $4000 for a vinyl sided garage. One entrance door and a standard 16' garage door, and no windows. Any upgrades are going to cost more. Then you have the price of the foundation on top of that. Any grading would be additional, but figure around $3000. Then if you can't build it yourself there is the cost of labor. Start at $3000 for that. Then the driveway to the garage will vary depending on how far and what is needed. And figure the hauling away of dirt if you don't have a place to dispose of it.. BTW is is going to be starting into the tornado / hurricane season before long, so figure the price of OSB will climb drastically. And all electric is in addition to those prices as is finishing off the interior.
Kevin