Lip products don’t have to be high end to work. Chapstick is the classic example and many people count on it (or Burt’s Bees).
My personal choice: Aquaphor. They do sell specific lip versions of Aquaphor, but I found that the formula wasn’t as rich. I buy these small tubes in packs of two and keep one on my nightstand and one in my purse.
The rich salve lasts through the night and keeps lips moist and soft. I always apply a light coat before any lip color during the day to ensure my lips are supple and smooth.