My advice is to shop around. Don't get 3 estimates and then stop. Talk to people, get word of mouth recommendations, give the smaller contractors a fair shot. Get references from your contractor and follow up on them. I know its a PITA but it will pay off.
I spent 3+ months researching local contractors and getting bids before I finally pulled the trigger. My first 3 bids were all around $40k, which led me to believe that was about standard price for what I wanted, and normally I would have have just eeny-meeny-miny-moe picked one of the three, except that it was a lot of money and I wanted to be a bit more diligent about it.
I wanted either a metal building (a real one, not a chincy enclosed carport) or a pole barn, insulated, and built to appease Texas Windstorm Insurance requirements (I live in hurricane country) so I could get it certified and insure the building and contents; this means the building and foundation is delivered with (and more importantly built in accordance with) blueprints stamped by a licensed architect. This drives the cost up considerably over "Any Ol' Pole Barn, by Bubba."
I got bids from $15k (bubba) to $65k (Morton & similar). The bubbas out there, half of them didn't even know what I was talking about with windstorm coverage and I'm sure the barns they built would have been ok, but not when I have my livelihood inside that costs more than my house and can't get wet. The Mortons (and similar) are not always the best! They build good buildings, yes, I went saw some of them, but other smaller local contractors can build just as good, and usually for less. You're paying for a name. Granted the name stands for dependability and a good history, which really is important, but you need to decide for yourself how much that name is worth.
After getting probably 20 bids, I ended up getting mine built turn-key for $30k by a local small contractor and have been extremely pleased. The research really paid off. I have a drawings folder probably 1/2" thick with each page stamped by P.E./architect documenting every little bolt and nut on purlin 6a of the West wall, the tensile strength of the guy wires, every facet of the 6 footings 6ft below the foundation, it's all there, and my stuff is secure & insured. The building is every bit as good as a Morton (dare I say better) and was half the cost. Engineered from (below the) ground up to withstand 130mph sustained winds. Truth be told I'm not sure how the contractor made any money on the job. But he named the price and I didn't even try to negotiate, so if he lost, that's on him. I was very leery about the low price; it felt "too good to be true" so I was very thorough with his references. I went and looked at buildings he claimed to have built, spoke to the owners, and confirmed his work. He seemed legit. With only a little reservation left in me, I finally wrote the check to begin the project. It was a great deal.
