A tech blogger has managed to get hold of some price lists that could be for the upcoming Microsoft Surface Book 3 devices. The listings also included prices for various related accessories and possibly the Surface Go 2. It has been opined that the "Surface Project T" could be the 13.5-inch Surface Book 3 while "Surface Project U" could be the 15-inch model.
https://www.notebookcheck.net/Potential-Microsoft-Surface-Book-3-prices-revealed-for-both-display-sizes-and-multiple-configurations.461355.0.html