Yes. It's really important to be selective in what you choose to oppose, but just because you're opposing certain social norms doesn't automatically mean you're invalid. They deserve objective analysis.

My wife and I have been married 4 years now and gone primarily without rings. No negative consequences so far, and I'm definitely glad I didn't dedicate 20%+ of my income to a valueless trinket. We have objects that signify our relationship, but they're cheap or free, and imbued primarily with sentimental value only. This is, in my estimation, much better than propping up the diamond myth and cartel.