How much of that first vial was paid for by taxpayers?
Does a single drug and associated trials really cost billions to develop? That's a year's worth of pay for 10,000 scientists at 200k/year (I suspect this is a rather high rate for most phd researchers). Most research teams are < 10 people [1]. You could fund 500 large research teams working on different drugs for 2 billion for a year. Let's say just one team, that funds them for 500 years.
Obviously there are other costs (rent, equipment, materials). But where is that money going? It doesn't seem to be going towards doing the science. It's extremely difficult to find breakdowns of R+D costs - seems to be a tightly held secret at big pharma.