Earlier quoted context omitted.
Indeed it's easier to value time over money if you have a lot of money and your time is highly valued.
... but it should be noted that there's a leveling-off as well. Once you're basically living comfortably and have the requisite free time, more money alone doesn't actually make you any happier. (Too tired to look up the research references, but I'm pretty sure there are some pretty solid findings out there on e.g. lottery winners, wealthy people, etc.)
There's some evidence that the former measure plateaus at some income level, but there's also significant evidence that the latter doesn't: http://www.pnas.org/content/107/38/16489.full