Ebsmom. I did the same thing as most of us have done.
I kept a book with floorplans and kept track of how much they sold for.
The lots with no upcharge are ones that back directly on another house. The prices go up due to views and privacy.
Backing directly on another house has it's ups and downs and most people focus on the downs. It is nice a safe feeling to have someone your own age behind you. Most backdoor neighbors don't have wild parties or throw trash in your yard and many backdoor neighbors share their stuff with you like a too big Birthday cake and show you pictures of their grandkids...who they think are cuter than yours...but they are too polite to say it.
Every home and yard and view and placement here is new and nice and fun. Except for that one place in the other village who lives next to the grouch.