Definitely. Sleep and nutrition are so important for health and longevity. I hate my grocery bill, but I'm going to continue eating mostly single ingredient foods. 

Aardvark

AskSN

What things are absolutely worth spending extra on?

Mattress is a good one. Not only do you spend a ton of time there, quality sleep is so important for general wellbeing.

I put quality food in this. That's another major part of life that impacts general wellbeing, beyond the immediate sensory enjoyment.

With both of these, I think it's a pay now and feel good vs pay more later and feel like crap situation.