The only option the company has is to sell. If they don't, they lose all their investor money and go bankrupt. The reason other countries get away with obscenely low prices is because the good'ol USA is paying for it, and the companies are better off getting anything other than 0.
If you look at how well industries are doing, you would also see that you would actually make more money investing in a burger chain than in the pharma sector. These high prices exist because of the incentives the insurance model creates (i.e. save people at any cost), not because companies are super greedy or evil and make 1.99$ million profit on a 2$ mill drug(which they do not).