Why are mail order (stock) plans so much cheaper?
House plans are expensive to create but cheap to reproduce. Therefore, the more times you sell a plan the less it cost. If you can find a stock plan that you like then you could save some money. Unfortunately geographical area and code requirements are different in every city, county and state. If you buy a stock plan be sure it complies with your local codes, that it comes with complete construction documents and can be built as drawn. Stock plans often have spacial conflicts, missing specifications, etc.