There are three big questions that you haven't provided answers for, but that will determine the pricing of a kit because they determine the fixed costs:
What configuration do you want -- how many drums and approximately what diameters? Are you talking about a 3-piece shell pack, 4-piece, 5-piece ....? Small drums, large drums?
What's your expectation of hardware selection? Quality and price tend to be related for this aspect.
What kind of wood and construction do you want? The more exotic the wood, or the more unusual the configuration, the more it's going to cost. Keller maple is probably the most affordable of the high-quality shells, and low-quality shells are not worth buying. Getting into other woods, multiple species, or solid woods will increase the cost. Thinner ply shells will cost less than thicker ones, but there's also a big difference in sound.
If you're not in a position to finish and build out the kit yourself, then you need to allow for labor and finishing materials in the total cost. Adding up the parts cost is not going to give you a real number, because a builder is not going to charge only for his out-of-pocket costs. Somewhere along the line, he's got to pay for having tools and expended materials (sandpaper, applicators, stains, varnishes, bits, etc.) that get used to build your kit, as well as something for the hours of work he puts into it.
More information in the form of answering those three questions can give you a more realistic number as well as some direction toward a builder who would be a good match instead of just shopping by price.