As a motorsports professional (I engineer roadracing cars), and having opened up a number of current Fox and RideTech (built by Fox) models, there is no way I'd pay for them.
Bilstein is doing the best job of building longevity into their shocks. If you are going to buy HD yellows or Sports, expect about 50k miles of street use. 5100 or 5165-style, about the same mileage, but better for offroad use.
FWIW, I change shocks when I change tires. They wear out about the same time.
------ Follow up post added September 22nd, 2017 10:30 AM ------
Originally Posted by rover4x4
I replaced the rears on my classic with these as I had blown a OME, figured these were made in muricuh. I ended up sending one back as it was built upside-down
Not made in America any more.