After five years of use my last peony ring resembles the after-affects of a coathanger mating with a blender, but unless the Lee Valley one plans on weeding my entire garden in it's spare time, I'll stick to the $5/pop variety. I really don't like them as I often wait too long to reign my flowerbeds in and the rings aren't really built to open around the bushes. In a perfect world I wouldn't spend the 1st weekend in June cursing while taming my backyard jungle, but I'm willing to admit Martha and I travel in different gardening circles.
Really, doing the math I'll get 40 years of well supported peonies with the occassional trip to Canadian Tire. Hubby would be so proud!