I understand that it takes R&D to develop new drugs, but the amount of profit sought by drug companies is stomach churning.
I sell digital, single-player video games. My manufacturing cost is zero and markup is infinite.
1. Producers and consumers are both equally informed 2. There are so many producers and so many consumers that no single producer or no single consumer is able to appreciably change the market price
Neither of those assumptions hold with the the drug market. Drug makers are massively more informed about the benefits and side effects of their drugs than I am. And there aren't that many drug manufacturers - and ongoing mergers keep shrinking the pool. In reality, the drug market is a barely regulated oligopoly, where a few large players manipulate the price signal to coordinate behavior so that they can move in relative unison to screw over the consumer. It's just like oil companies or airlines.
Your manufacturing cost is not zero at all. You have significant fixed costs; your marginal cost is zero, or so close to it as to be negligible. Your average fixed costs fall with each copy sold, but unless you consider your time and labor entirely worthless you have to sell quite a few copies before you break even.
Also, since your game is a discretionary expense, there's no significant opportunity cost to the non-purchaser, whereas the opportunity cost to someone who eschews or can't afford to purchase medication might be the person's life.
What's the right amount of profit a company should seek? For reference, following are the latest reported profit margins of several companies:
Eli Lilly: 20.34% AstraZeneca: 13.33% Novartis: 17.33%
Apple: 19.53% Google: 18.11% Microsoft: 24.95%
It's not at all clear to me that drug companies are somehow seeking more profits than other companies (or that they would generally be able to attain them in any case).
Could it be high-level tax evasion ?
It's not only profits: lifestyle drugs, like statins and medication for ED are obviously a source of easy profit, meanwhile research into antibiotics is falling by the wayside.
The fact that the existing antibiotics are becoming useless and there is nothing to replace them is going to be a disaster. There is this current discussion about vaccination skepticism (to use a polite word); one reason that parents omit to vaccinate their children is that no one living has experienced what a genuine measles or polio epidemic is like.
The availability of antibacterials since the 1930s has been a similar miracle. You do not have to die of a severe infection, you can take medication against it. Unless there is investment in research, serious infectious diseases will be back.
Remove advertising and reduce prices accordingly.