I wear kilts almost daily (except at work where I have to wear a uniform while on duty).

I've been holding at 11 kilts (while I decide on what the next will be).

7 Utilikilts - 3 Workmans (khaki, black, caramel), 2 Original (tan and urban camo), 1 black Mocker, 1 original black Leather
1 Bear Kilt - Hunting Stewart tartan
1 Pittsburgh Kilt - Flannel-lined blue denim
2 Stillwater Standard Kilts - Black Stewart and Nightstalker tartans

Unlike jeans (and other trousers) kilts don't have knees or crotches to wear out. After seven years of heavy wear, my first kilt (black UK Workmans) is only showing some wear on some of the belt loops.