I looked into building a house, but where I live, current homes are much cheaper. We have a contract for a house that's less than $150/square foot, which is a great price here. Keep in mind that this price includes landscaping, the land, etc. Lots in the same area run almost $200,000. And builders say the minimum they can build for is $200/square foot and they say a more realistic value is $225+/square foot. So, if you could get a reasonably priced lot where you could get it cleared for a total price (lot + clearing) of 200k, and built a 2,200 square foot house, you'd be at $640,000-695,000 and you haven't dug the hole for the house and you don't have any landscaping. You're looking at 700,000+ easily, which in many areas around here makes your house several hundred thousand more than the other houses on the block. So, where I live, it's just too expensive to build a house right now.
It's good you can build. There are a lot of options for building. I've been looking into Green/passive homes. Since you're building, you could incorporate a lot of those concepts and not spend a huge amount of money (relative to me, where I have to retrofit). For instance, you can insulate the outside of the basement/slab; add thicker walls with more insulation; seal the attic; add a heat/energy recovery system; etc. All of that stuff is possible to retrofit, but it's harder to do.