If 14 months ago, they were building them for $450,000, I'd wait.
I'd shop around for another contractor too. A young guy starting out, might save you a lot. (There's no way to verify he knows what he's doing though.)
If you are some what handy, it's not that difficult to owner build your own house. That is if you get the blueprints past the town's council. Getting approvals is the tough part.
If you get all the town, county, approvals, and have a very buildable lot (flat, no flooding, etc.). Once the foundation is poured, it step by step, and done.
(If you decide to build yourself, don't make any changes. Don't build a custom house either. A simple home will make the process go smoothly. Realize too, the General Contractor just hires licensed subs, and takes a healthy cut off your nut. Then again--if you have never done construction yourself, disregard everything I said. I just pictured a typical computer developer in a wet lot, with an unhappy wife. Muttering to Google translate to communicate with the unlicensed, unbonded, subcontractor.)