Subdividing already owned land to build a new house?

My wife and I decided we may want to move into a bigger house in the next few years. Our current house is on a 13 acre awkwardly long lot, where the first acre is house/lawn and the back half is woods accessible by a private road from our neighbors. We almost have this house/land paid off and were thinking about seeing if we could subdivide this lot off, clear out a spot and build a nice new home in the back half of the property and sell our old house. Because we already own the land, I figured it would save a lot of money rather than buying a new house/land. I've read that building can be a nightmare/expensive. As someone who knows nothing about the process of ANY of this (I'm an IT guy, and not handy...) Is this a bad idea? What are the pros/cons? Would we actually save money to build on our land and do all of that? There aren't many lots of land for sale in our area but decent ones can go for 150-200K (Maine). We already love our town and the area, and we would be able to carve out a custom wooded area so we'd have no surrounding neighbors, which would be nice.

I know it heavily depends on prices in your area, is the land even any good, etc. but figured I'd see if we could get a general sense of people's experience with this.