I am currently finishing the inside of a Morton building. The core building was 30 x 40 with 2 garage doors, concrete floor, about $23K. I am adding power, water, air, insulation, and then plywood walls both for protection and to mount things too. I am happy with the job Morton did. It's taking a _lot_ of my time to do this interior work. You pay in time, or you pay in money.
I would have gladly paid more for stick built that matches the house, but have no idea who locally could do it. The house is 2.5 years old, but wouldn't want the group that did it to do a garage. Tried a local contractor to do repairs on the old house that's now on the market, they messed it up. I know 2 people who build houses in the 2006-7 time frame, both had big trouble. The repair work to the old house was not a great deal cost wise. So I settled for a building that doesn't match very well, but it's OK. I think both the building and myself are looking at a 25 year life span, then the next owner can either scrap it or take the skin off and finish it to match the house. The roof pitch and orientation of the peak matches the house, so it could be cleaned up easily.
When it's all done, I'll post a thread on the project.
It seems like more and more that if you can't be assured you're getting quality, you just go for low price and disposability. Tools are either Klien or Harbor Freight. Since the volume is at the low end, the cost of quality keeps going up. And if you're outside of your expertise, it's very hard to know if you're getting quality. Wall mart is not winning solely because of it's low price and people's cheapness. Part of it is a general lack of quality in the world that forces a low cost throw away mentality.
The OP had confidence in a builder, so I'd go stick built and get it right and make it match. This also means you must specify exactly what you want. Part of why Morton was easy and cheap is because it was a box with doors. When you toss in matching finish, colors, electrical, water and interior trim work, you must be precise., Break out each category as it's own cost so you can better oversee the project.
I know a lot of workers are hurting around here, but it seems like they'd rather starve than drop their prices. I suspect they are buying their food at Wall Mart. So I'm using my time instead of hiring someone. I'll save my rant about general contractors and architects for a more on theme thread

.
Pete