Lipitor is a brand-name medication that contains the active ingredient atorvastatin, which is used to lower cholesterol levels in the blood. According to DrugPatentWatch [1], the patent for Lipitor expired in November 2011, allowing for the production of generic versions of the drug.

The cost of generic atorvastatin, however, can vary significantly. As noted in an article by the University of Oxford's Bennett Institute for Applied Data Science [2], some generic versions of atorvastatin are "ghost-branded," meaning they are produced by the same manufacturer as the brand-name drug but marketed under a different name. These ghost-branded generics may be more expensive than other generic versions of atorvastatin.

The New York Times [3] reported in 2011 that Pfizer, the company that originally manufactured Lipitor, was offering discounts and incentives to encourage patients to continue using the brand-name drug rather than switching to the generic version. This suggests that at the time, the cost of the generic version of atorvastatin may have been lower than that of Lipitor.

In conclusion, while the patent for Lipitor has expired, the cost of generic atorvastatin can vary depending on the manufacturer and marketing strategy. Patients should consult with their healthcare provider and pharmacist to determine the most cost-effective option for their individual needs.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LIPITOR
[2] https://www.bennett.ox.ac.uk/blog/2018/12/ghost-branded-generics-why-does-the-cost-of-generic-atorvastatin-vary/
[3] https://www.nytimes.com/2011/11/30/health/generic-lipitor-sets-off-an-aggressive-push-by-pfizer.html