I have spent my whole life mostly buying nothing and I realized recently that I am probably pretty far from optimal on that tradeoff. Outside of food, rent, and travel I've been spending around 5k/year my entire life (mostly laptops and phones)

Recently I realized I'd probably get old with money better spent while I'm young, so I started spending a lot more. It's felt great overall, for example I bought a sleep tracker, new bedding (had been using the same pillows for 12 years), humidifiers, air filters, CO2 monitor, and a few other things to sleep better. It made a noticable difference on my sleep.

Probably many people reading this site actually buy too little.