It looks like all the ones in the $1-3k range are unfinished to some degree. You'd need to get electrical wiring, insulation, drywall and flooring. It gives you

It looks like all the ones in the $1-3k range are unfinished to some degree. You'd need to get electrical wiring, insulation, drywall and flooring. It gives you a few different options for exteriors and space to buy one and more customization options, you're going to need to put in some manual labor somewhere along the lines so the question becomes: is it better to spend ~$10k for a fully finished product, $1-3k + parts & labor for a prefab or hire someone to build the whole thing from scratch? I don't know what it would cost to hire a contractor to make something like this, but these pre-made options give you a good idea of where you might want to draw the line on pricing.