This is a pragmatic approach to the reality of the situation: Disney and other large copyright holders have historically been able to leverage their position to increase copyright
universally to absurdly long levels. The idea of a COST based mechanism for copyright tries to address a few practical approaches to copyright:
1. Copyright that's not assigned value defaults to the public domain; this provides an avenue for copyright to devolve to public domain immediately which does not currently exist;
2. Copyright that's no longer maintained by its owner devolves to the public domain (similar to 1), taking it out of "copyright limbo";
3. Any group with sufficient resources can take a copyright into the public domain as a public good, e.g., "we" could buy Wolverine into the public domain;
4. Copyright can be maintained for very long durations for entities that choose to do so;
5. The ever-increasing cost means that eventually the copyright "buys itself out", that is, when the COST is assessed at 100%, the Fed has sufficient funds to simply buy the copyright outright (this is a choice, btw, the Fed could happily accept 130% of COST!); and,
6. Absurd copyright lengths no longer universally apply.
I think (but I've not completely thought this through) that such a system could help with patent litigation. Specifically, consortia of entities can buy out a patent if the patent is weaponized. Mind you, the patent holder can no longer "squat" on a patent for free: they must pay the COST of a patent portfolio! This naturally handles the asymmetry of costs between NPEs and regular old entities.