Admittedly, the online Den Resources Guide looks good, but I did have to chuckle at the "no printed book because that is a cost to bear to deliver the program and we're trying to remove these barriers", and yet, if your pack requires the full uniform for each Cub:
Lion $74 (tshirt, cap, belt, neckerchief, slide)
Tiger $130+ (field uniform, socks, council patch, pack numbers, world scouting movement patch, cap, neckerchief, slide - extra if you want standalone shorts, new Cub needs belt etc, slightly less for girls as the girls roll-up pants or skort are cheaper than the switchback pants)