Where do you shop for beauty products?

Where do you shop for your beauty products? I went to Costco to buy some BBQ stuff a few weeks ago and I went to the beauty aisle and I came across a SmashBox kit. It was like under $20 (I think it was $19.99) I got a mascara, a mascara primer, 3 mini lip glosses and a case to put them in, skin tint and an 4 color eye shadow kit. I thought it was a great deal? Do you shop for beauty products at places like Costco, Sam’s Club, BJ’s or other warehouse store?