Dr Jubilee
Dr Jubilee can be found in NCR hospital building. He offers medical supplies and is very keen on sharing knowledge about Doctor profession for caps. He does not buy much but he will take some drugs.
You can buy from him followed blueprints:
Stimpak - 2500
Super Stimpak - 6500
RadAway - 6000
Rad-X - 8000
Needler Pistol - 15000