STUDY: CVS, Rite Aid, And Other Chain Pharmacies Sell Generic Drugs At Up To 18 Times Their Cost | ThinkProgress. I was talking with a friend about what drug store chain was the most socially responsible. She said that CVS was most responsible because they don’t sell tobacco products, but I did some research and this is the result. CVS is the most expensive to buy pharmaceutical prescriptions. Go Walgreens!