Are you aware of the Back 2 MAC recycling program? Bring back any 6 glass, plastic, or metal makeup products (finished or unfinished) to any MAC counter, and in return for them you get to choose any lipstick you want, for FREE! The only lipsticks excluded are Viva Glams, as their full selling price (not just proceeds) go to charity.
Don’t forget that the foil wipe containers, eyelash boxes, and retractable lip pencils also count! More or less the only things you can’t trade-in are sharpeners, wooden pencils, and brushes. And if you bring your 6 items into a MAC store, instead of the lipstick you could choose a lipglass or eyeshadow!