A lot will depend on how much time, labor and equipment you have available to raise the structure. Buying the materials and building your own would be cheapest. You then have the ability to select the materials you prefer, and those suitable for your location, assuming you can get them.
Prefab is the next cheapest approach but still requires the necessary labor and equipment.
Where I live, it's hard to beat outfits like Pioneer Pole Buildings for price and labor savings. Their website may give you ideas and prices which will of course vary with location:
Pole Buildings 1-877-POLE-BARN Top Quality Pole Buildings at a Great Price! Post Frame Precision Pole Buildings Serving PA, NJ & MD
www.pfppolebuildings.com