Some different points of view might help? Most of these are on the high side of average.
https://www.campendium.com/lees-ferry-campground
I've been through there on my way to North Rim a handful of years ago. I remember the Navajo bridge as being pretty spectacular with native flea market type tables at one end selling stuff. other than that we took a few pics and then continued on our way. We never actually checked out the campground. Sorry. Maybe next time we will.
Mike. Comments are anecdotal or personal opinions, and worth what you paid for them.
2018 (2017 Sprinter Cab Chassis) Navion24V + 2016 Wrangler JKU (sold @ ????)
2016 Sunstar 26HE, V10, 3V, 6 Speed (sold @ 4600 miles)
2002 Roadtrek C190P (sold @ 315,000kms)