Though it's sometimes true that drug patents come from universities (though certainly not the only source of drug patents), you have to be completely clueless about clinical trials to say that marketing costs are the only considerable expense.
Let's say you get a 100 drug patents from university, you will refine purification and production methods for at least a few months and you might select 10 based on multiple criteria including in vitro toxicity for clinical studies. From those 10 drugs, maybe 2 or 3 will go to clinical trial phase 2b-3 and if you're really lucky, one will end up on the market. Clinical studies for safety and efficacy of drugs are VERY expensive and have low chances to yield a drug. This is in part why commercialised drugs are so expensive.
That said, I certainly won't defend Big Pharma and say they are poor and need more support, but just keep in mind that there is a lot more to drug development than "freeloading" public university research.
