Obamacare actually increases the cost of drugs. Here is a study showing the comparison adjusted for inflation.

https://pubmed.ncbi.nlm.nih.gov/28224469/

For some single source drugs the suppliers absorbed some of the subsidies, while others and generics were cheaper for consumers. It is unfortunate that sometimes customer facing subsidies get abused by single source suppliers.

This study is not about drugs per se, but only some oncology drugs that were popular in 2006. It even states "however, generic oncology drug prices showed no significant changes" in the abstract.

That’s selective quoting. The study states in the abstract the top selling drugs saw price increases. Here is the full abstract.

> The results show that the average annual price of top-selling cancer drugs in 2006, adjusted for inflation and secular changes in drug prices, have increased by US$154 and US$235 for branded and competitive brand drugs, respectively, following the 2010 ACA; however, generic oncology drug prices showed no significant changes.

The top-selling branded drugs price increased. Generic drug prices (the relevant comparison to Cuban's Cost Plus) showed no significant changes.