I would be in favor of a fee that is 1024 * 2^n USD where n is the nth year you want to keep the patent. 1st year = 2000 USD 10th year = 1m USD per year 20th

I would be in favor of a fee that is 1024 * 2^n USD where n is the nth year you want to keep the patent. 1st year = 2000 USD 10th year = 1m USD per year 20th year = 1bn USD per year It becomes prohibitively expensive if you don't use it. After 23 years it would make only sense for the most insane blockbuster drugs to keep going for another year.