I've lived for years without buying a new lip brush. I use a lip liner with a brush on the opposite end. I have a few of those and they have served me well so while I've thought about spending money on a lip brush, it was never felt like a necessity. That changed when I saw Chanel's new retractable lip brush. I was in love.
The associate showed me this brush when she was rolling out the display for the brand new brushes. It was a little black thing, about 4 inches in length. Out it came from the black velvet bag, she uncapped it, twisted up and there it was. The lip brush.