"I've earned it"
Some keeping up wears the clothes of a reward. The hard year, the promotion, the bonus. The kitchen isn't matching. It's what you've earned.
Rewards are fine. I'd have more of them, not fewer, in most people's lives. What I'd ask is which reward. The reward you'd have chosen alone, at the end of a hard year, with nobody's kitchen in your head, is a reward. The reward that arrived after dinner at the neighbours' and took the shape of their extension is a match wearing a reward's name.
Here's the test, and it's the same one as chapter 8's. Take the thing you're calling earned and ask whether you'd have wanted it if nobody were going to see it. A holiday somewhere you've always wanted to go passes. A holiday somewhere the colleagues went passes only if it's also somewhere you wanted. A car that does something your old one doesn't passes. A car that does what the old one did but newer, on the drive at work, doesn't. The test isn't about cost. Some earned things are expensive and pass easily. It's about where the want came from.
There's a second test for a reward, which is whether it's enjoyed. Quoidbach's finding from chapter 8 is the caution here. A thing bought in a frame of comparison is a thing bought with a reminder of wealth attached, and the reminder blunts the enjoyment. The earned kitchen that's also the matched kitchen gets enjoyed as a match, which is to say for the year until next door's is newer, and then it's a kitchen.
So keep "I've earned it", and spend it, on the thing you'd have chosen with your eyes closed. That thing will be enjoyed the way rewards are supposed to be, and it'll usually cost less than the match, because the match has the neighbour's price on it and the reward has yours.