I think value is an individual metric. E.g., I value good chocolate highly, but chocolate gives my girlfriend migraines, so for her it has negative value. So I think the time of rich people is exactly as valuable to them as it is to poor people. Or maybe less so, in that the rich people I know are on average much more willing to waste time than the poor ones.

Given that, your other schemes are more plausible, but I don't know that they'd be better in practice; the nth-order effects are hard to calculate, but could easily be pathological. Given that the real problem in doing this is the way some people have orders of magnitude more money than people, the cleanest solution is just to tax heavily enough that the wealth difference isn't nearly as large. Which, given the sensitivity of US politicians to the desires of the wealthy, is entirely unlikely to happen.