Ethical engagement rings for under $500

Hi everyone. My boyfriend and I have been talking about getting engaged soon and have been trying to find some engagement rings that we both like. I am pretty low maintenance (hence being on this sub haha) but my boyfriend still wants to splurge a little since I'll be wearing it forever, so I thought $500 was a good compromise for budget.

My only requirements are the metal being one of silver, white gold, or platinum, and that the stones be ethically sourced. Lab grown stones or cheaper non-precious stones are all good with me.

Does anyone have some recommendations for stores or independent sellers that would have <$500 options? Or is that price point not realistic.

Thanks!