I'm not seeing anything described in the article as "buying time" that couldn't also be described as "buying the right to order someone else around" aka "delegating". Surely the most direct way of buying time is by taking a pay cut in exchange for more time off, or even taking unpaid time off. It occurs to me there may be a good proxy for this in comparing similar tech jobs in the US vs the EU / UK. The latter pay less, but receive substantially more time off.