Well, I can't say I never got my moneys worth out of this $4 shift cable.
I've had my Madone for almost 2 years now and have never changed the cables. I guess that's since it's my road bike and it never shifted poorly on me once, but the last few rides have been hell.
The cable was so frayed I couldn't even pull it though the shifter. Ended up cutting it again and pulling it out strand by strand.
I must swap cables on my mountain bike at least 3 or 4 times a year if not more, I have never let one go this far, Leonard Zinn would be so disappointed.