After buying from the merchant at the Mojave outpost bar, My game kept CTDing. I finally found a specific item that would always crash my game when I'd buy or soon after. The merchant was selling duplicate caravan playing cards "2 of clubs - lucky 38 (2)". Whenever I'd buy both cards my game CTDs.

http://steamcommunity.com/id/rcrobert/screenshot/540654888632999554

Mods
All DLC
Light Step ED-E.esp
GoodspringsFarmhouse.esp
MTUI for FalloutNV