The widest gaps are on cancer drugs.

Generic imatinib is the drug that made chronic myeloid leukemia survivable — a decade of patent-protected Gleevec sales at five figures a year, then a generic that costs very little to make. Cost Plus Drugs sells a month of it, profitably and transparently, for $34.50: acquisition cost, plus 15%, plus flat fees.¹ The same product page lists the retail price at other pharmacies at $9,657.30.²

That 280-fold figure is Cost Plus's own comparison, so treat it as the company's number. But the independent evidence points the same direction, and it clusters in the same place: oncology. Researchers writing in the Journal of Clinical Oncology projected that Medicare overpaid by $661.8 million a year — 78.8% of its spending — on just seven generic cancer drugs relative to Cost Plus prices. Abiraterone alone accounted for a median $338.0 million, imatinib 400mg for $212.0 million. For an individual patient, the projected saving was roughly $25,200 a year on abiraterone and $17,500 to $20,500 on imatinib.³

Why does the gap concentrate there? Volume and desperation run in opposite directions. Statins and metformin move in such quantity that even discounted cash markets stay near cost — the index shows metformin at parity with its coupon floor. Specialty generics move in small volumes to patients with no alternative, through supply chains where, as the FTC documented, the pharmacy collecting the markup is often owned by the middleman that set it.⁴ That dynamic is the subject of Briefing 02.

The broader arithmetic was established in Annals of Internal Medicine back in 2022: Medicare could have saved up to $3.6 billion — 37% of its spending — on 77 of 89 studied generics in a single year at Cost Plus prices.⁵ The prices have been public for four years. What has been missing is the instrument that keeps the comparison in front of people continuously, ranked and readable, rather than once per journal cycle. That instrument is the index on our front page.