"Super" expensive? That's expensive!

Roofline and corners. That's where the money is. Well, that and interior finish selections.

Different rooflines add up fast. I didn't realize it but (in my area, at least) dormers end up being ~$2k each. All that for basically a window.

Yes it looks expensive to build, or rather inefficient, it will be quite a bit of money for the square footage you get.

A few things I have learned as I picked a plan scrapped that plan and picked another.

1. Roofs are expensive. The cheapest roof is one peak and a gable at each end. Every time you add another peak to the roof you subtract a decent amount of money from your pocket. Although I can't see the back I count at least 8 peaks on your plan + 2 different types of dormers.
2. Straight exterior walls are cheaper than corners or round walls. The cheapest plans have four exterior corners. The plan you have has 24 corners, and quite honestly some of these corners are just for the neighbors. This is a gorgeous house but some of the bump-outs have no real impact on the interior of the house. For example, the small bump-out in the front bedroom/office adds no real value compared to just making that a straight wall all the way across. It shrinks the room, adds a roof peak and a lot of money for a slight aesthetic appeal. The same thing goes for the exterior wall by the pantry. You are basically paying quite a bit extra to shrink your pantry.
3. Exterior walls are somewhat expensive, so the most efficient houses maximize space and minimize exterior walls. This means the more square your house is the more efficient it is. For example, 4 walls each 40' long will get you 1600 sq.ft. for 160 linear feet of wall. Where if 2 walls are 25' each. the other 2 walls will need to be 64' to get the same square footage, so 178 linear feet. A combination of 2 and 3 gets you the famed fourquare home. Four corners - square design.
4. Since #1 exists it is usually cheaper to go up with your square footage than out.
5. Open floor plans are generally more expensive. Open floor plans usually take either more expensive joists or beams. This is a trade off that many think is worth it.
6. Cheaper if first and second floor walls line up.
7. There is a nice lake near where I live and on that lake sits a luxury house boat, it is named Change Order. Probably one of the most overlooked things is plan, plan some more, plan even more, think of everything, then think of everything else, then start to build. The more you change after you start the more money you are going to spend. And change orders are expensive.