The better aluminum wheels at $800-ish are about the same weight as the $1200 carbons (maybe 1600 - 1650 grams) so I'd save my money and go aluminum in this price range if they are significantly lighter than what you have. Otherwise I'd stay with your current wheels. For gravel you need something wider and stronger than road wheels so the super light carbon does not make as much sense as it does in road wheels. Light weight you will notice immediately but road feel you will have a tough time telling the difference in this price range. Easton, DTSwiss, are great aluminum wheels in this price range and Shimano GRX are hard to beat for $418 in the lower-price bracket.