Lipitor is a popular medication used to lower cholesterol levels in the body. According to Drug Patent Watch [1], the patent for Lipitor expired in November 2011, which means that generic versions of the drug are now available on the market. GoodRx [2] is a website that provides price comparisons for prescription drugs at various pharmacies across the United States. According to their website, the average retail price for a 30-day supply of atorvastatin (generic Lipitor) is around $15. However, prices may vary depending on the pharmacy and location. GoodRx also offers coupons that can be used to lower the cost of atorvastatin at participating pharmacies.

Additionally, NPR [3] reported in 2012 that some pharmacies were offering free Lipitor to patients with a prescription. This was due to the expiration of the drug's patent, which allowed for the production of generic versions at a lower cost. It is unclear if this offer is still available, but it may be worth checking with local pharmacies to see if they have any similar promotions or discounts available.

In conclusion, the cheapest place to buy Lipitor would likely be at a pharmacy that offers generic atorvastatin at a low cost. GoodRx is a helpful resource for comparing prices at different pharmacies, and they also offer coupons to lower the cost of atorvastatin. It may also be worth checking with local pharmacies to see if they have any promotions or discounts available.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://www.goodrx.com/atorvastatin
[3] https://www.npr.org/sections/health-shots/2012/09/12/160997059/how-cheap-can-lipitor-get-try-free