Much depends on local codes as mentioned. Options can push the price, too. We had a metal shop built. 20x30 Metal building with 12' walls, roof vent, one window, 2" insulation, water, 125A service and 10x10 roll up door. We live within 1500' of the coast line so gust load is 150mph for 10 seconds. Foundation was <$10k and building was ~$15k. Foundation was nearly 4' deep at cornered and mid beam supports. That was with steel mesh 4" floors.
I'd have put 6" floors if I had planned on parking anything heavier than a pickup. Find out what the local codes require on wind load for tornado in your area. Keep in mind the erection costs. You will have to have a crane or other lift to get roof beams in place, not to mention the higher girths and purloins. We had a high lift fork vehicle used by the erctors which was ~$1k for about three days delivered.