I ran my XPS RIBs for 6.5 years/40K+ miles and sold them on CL for 200 bucks with around 65% tread left. I hope to run my R250s as long or longer. The only reason I pulled the Ribs at 6.5 years was that one was 8.5 years from manufacture and was getting hair line cracks in the sidewall. The other three were 7.5 years old. Now I check date codes more closely.
I got 550 bucks up front from Kenda to remove their OEM chinese Kenda Klever LT bombs in the first year I owned the trailer/Feb 2005. So 550 + 200, and the RIBs really did not cost but a few hundred bucks.
Don't try that with a cheap tire.
Chris
Chris