Years ago my husband lost a lot of weight and managed to lose his wedding ring while washing his hands in a public sink. I rememer how pitiful he sounded when he called, and me gently laughing as I reminded him i married him, not the ring. We did replace both his and mine a year later when we renewed our vows, but to us, the rings are only a symbol, not the marriage.
I've known people who've used tatoos, necklaces, bracelets, or nothing at all to symbolize their vows. It's actually pretty common in fields where folks work a lot with their hands. Back when i worked as a massage therapist, I took mine off while working. I still do if I'm doing anything overly messy.
Being married is something that shows in how we act as much as any outward symbol. It's not the hand I watch to see if a couple is together, it's how they relate to each other and act independently that let's me know they're in a committed relationship.
That being said, what does the ring mean to you? We can all have an opinion, but how you feel about having it as a reminder is what matters most. If it's a comfort and reassurance thing, then pay the money and get it resized when you can, find a way to keep it close until you have the budget for it or a placeholder you can use instead.