I married my partner, after being with them for over a decade, and a few years of living together full-time. It was mostly for admin reasons (we just bought our home, and being married made things easier if one of us died). If it wasn’t for that I don’t think we would have bothered. We know we love each other, and had decided a few years before that if we’d get married if we ever needed to, so it wasn’t like we ever ‘proposed’. Just a tiny ceremony with two friends as witness, and we went out to a restaurant for lunch afterwards. I don’t think it cost us anything beyond lunch? Maybe a tiny admin fee?

But… I’m so happy we did! It’s weird! I never really cared, and rationally, I still think it hasn’t changed anything. But somehow it feels… really nice? I still regularly think (and tell them) “I’m so glad I married you”. I’m sure there are lots of other things that you can do to symbolise your relationship or commitment. If I got a tattoo inspired by my partner I’d probably have the same feeling of looking at it and thinking of them that I do when I play with my wedding ring (2€ piece of silly junk from aliexpress. And we each bought a bunch of spares so that when we inevitably lose them it’s not a problem). But actually a marriage is one of the simplest and cheaper ways (if you don’t choose or feel pressured into turning it into a stupid moneysink).

Tldr: didn’t care about marriage, got married for tax, and weirdly found it deeply satisfying in a completely unexpected way.