Ok now you made me double check :) My pc running with my normal apps takes 4.5 GB. I loaded the game up (with the WOTW mod which might be a hog), and I am now at 19.3 GB of memory used. So the game plus mods is 14.8 GB. Now, I suspect this is mainly because WOTW mod uses a lot of prefabs and...
Get 32 GB of ram. Currently my system + game uses over 16 GB of ram when playing this game with mods. So this would be the biggest price/performance boost if you intend to play mods or run with max settings IMO.