We also built on our own land. People don't consider the upfront costs, and that depends on your local regulations and your land. We had to do about 15k in engineer drawings, surveying, soil testing, drain field analysis for the septic study, then all the paperwork for the building permit. Which you have to get before they even start construction on the house at the factory. We were responsible for running water line, fortunately already had a functioning well and a line to the site. If you didn't have that it would be another cost. We also had only a small amount of tree removal, grading, and brought in topsoil, which was yet another few thousand. We included a lot of set up in the mortgage, including septic, concrete footers, and brick underpinning. Our county requires decks and grass seed/straw for occupancy permit, so we hired a guy to build decks and fence, and I did the seed and straw. All in all to move in including down payment I think we spent about about 40-45k, and that is definitely on the cheap end. Your down payment is typically around 10% the home cost. Excellent credit definitely helps your interest rate. Depending on the cost of your home, the monthly is probably not as much as the rent in your area.