If you're relatively handy, a lot of what OP paid for can be DIY'ed. I would have never paid a contractor to do all of that. Probably just the electrical. Especially the Tuff Shed structure. Those things are dead simple, marketed at DIYers, and can be finished in a weekend. Insulation, drywall, trim, and flooring is also child's play. OP could have easily cut the project's cost in half if he wanted to.

Yeah I had the same thoughts about what they chose to DIY vs hire out. Insulation is so simple, and trim can be done at your leisure. But thats also not likely to save much overall since the contractors also know how simple those are.