Old question... but answering for anyone who sees this later:
Something to consider when buying land and either building your own or hiring a contractor, is the time/cost associated with all the administration, "due diligence," and permitting issues surrounding land & lots which have never been built upon before.
There are procedures one must follow before constructing much of anything, especially on raw land, and it's very time consuming - there's also more "risk" involved, as there's no guarantee you'll be able to utilize the land and build upon it as originally intended. When purchasing from a builder however, part of what the buyer is paying for, is to reimburse the builder for all of these previous expenses - in actual dollars, time, and the risks associated with development... and it's reasonable for the builder to expect to profit on these efforts.
So, before setting off to build on land you already own (or will buy soon), be sure to consider your own time, and the potential risks... as those aspects have significant value just the same.
Anthony Gilbert REALTORÂ®
The REALFX Group at Windermere Real Estate East/Inc.
14405 SE 36th Street Suite 100, Bellevue, WA 98006