buying my own promise ring?

I've talked to my boyfriend about buying him a promise ring, and he's totally all in for it. He said he doesn't want to wear one if I don't have one. Like a couples ring! I agreed to buy both his and mine if he only picks out the one he wants me to wear. He's currently saving up for a newer car and he is financially tight. We aren't buying super expensive ones, just ones that won't turn our fingers green 😂 id rather buy nicer rings for marriage. Is it weird buying my own ring? 😦