If the price of a drug then is 50x in the US (as in this case), and the US buys it at the same rate as the rest of the world, then sales to the US would account

If the price of a drug then is 50x in the US (as in this case), and the US buys it at the same rate as the rest of the world, then sales to the US would account for ~70% of the revenue. To attain the same revenue with a constant global price, would require an increase of just over 3x of that lower non-US price point. The original characterization ("What we should be pushing for is a change in circumstances that get those in other countries to pay their fair share so Americans don’t bear the entire burden of incentivizing bringing drugs to market.") doesn't seem particularly incorrect.