Generally I never buy them as well, in fact, this is the only time I think I have. At the time, I was concerned about buying CFMOTO and as has been pointed out, repairs don't take long to get into the $1k range or more. Can't remember exactly what I paid, but it ended up being under $200/year, and that seemed like reasonable insurance.
Edit: I went back and looked at my sale paperwork and I paid $800 for 4 years of extended warranty. Rider's Advantage. I forgot what their initial quote was, but I remember flatly declining it, and then they offered the reduced amount.