Well ideally the patent holder would simply license his patent to you and cover his costs/profit on his invention. But I agree the system is ridiculous and arbitrary (20 years in the IT is probably 100 years in some other fields :)).
I think the best way to deal with patents is to make a 4 year patent free period, in which you can file for new patents, but you can't sue anyone for infringement, and any work within those 4 years can't be affected by existing patents after the period expires. AFAIK this was already done by the US government in the aviation because they didn't want to pay Wright brothers, and the aviation industry grew, but I read this a long time I don't remember the details. But essentially you can measure the R&D investments in the industry and provide a empirical argument on how much R&D investment was lost (if any, I think the effect would be opposite, but it's a speculation) and compare with how much the industry has grown, then if you come to conclusion that patents are necessary measure the average R&D investment cost, profit, return periods, and compile that data in to a optimal time period which would allow the average successful/profitable patent to recoup the investment and earn a premium on standard rate of return.
I think the best way to deal with patents is to make a 4 year patent free period, in which you can file for new patents, but you can't sue anyone for infringement, and any work within those 4 years can't be affected by existing patents after the period expires. AFAIK this was already done by the US government in the aviation because they didn't want to pay Wright brothers, and the aviation industry grew, but I read this a long time I don't remember the details. But essentially you can measure the R&D investments in the industry and provide a empirical argument on how much R&D investment was lost (if any, I think the effect would be opposite, but it's a speculation) and compare with how much the industry has grown, then if you come to conclusion that patents are necessary measure the average R&D investment cost, profit, return periods, and compile that data in to a optimal time period which would allow the average successful/profitable patent to recoup the investment and earn a premium on standard rate of return.