That sounds like a pretty cool idea.

After 30 years if it's not generating $1B a year you let it go. That would make most creations pretty cheap to keep for the first 15 years, corporation level expensive from 15 years to 25 years and global phenomenon level only after 30 years.

If that sounds too aggressive maybe double it only every 2 years.

The US is allowing Disney to become a behemoth of a company without competitors, so even if the price rises up to a million trillion gajillion dollars they would be able to pay without much effort.