Well... if I was going to build a steel garage I would want someone to at least come out to give me prices and ideas.
Not being from your area I have no idea on costs.
Having a couple of folks come out and explain options is always good. Getting a professional to start the foundation is always better. Most of the time you end up with less headaches. This is good for when the building goes up and it is level and plumb.
Nothing worse that chasing a building around the foundation.