John, not so much affordable but I went with a Delsey Helium rolling duffle bag because I’m always right at the airline weight limit and yes, carrying dive gear, cameras and carry-on thru the airport and parking lots gets old real fast.
Another option would be one of those folding luggage hand trucks to put your existing duffle on but then that’s more weight and unless you can bungee it to your carry-on the airline may charge you for another piece :(
I had a divebuddy who packed everything, everything!, clothes, dive gear, camera for a two week dive trip in a backpack with the fins bungeed to the outside with her exercise bands. Except for the fins it still fit inside the carry-on size box in the check-in line :) Okay, a woman can get away with wearing a lot less clothes than us, sometimes at dinner it was little more than the bathing suit cover-up.