If it's a true CPO (factory demo or refurb), that's an excellent deal and I'd jump on it. The grip should be wrapped with a blue paper band and the pistol will have a red box rather than usual Sig blue.
I've had a P226R CPO for a couple of weeks, it looks good as new and saved me a couple of hundred bucks. The only issue is that the slide only locks back half the time on an empty magazine (and I didn't think to test each mag at the range last time, to see if slide-lock worked with one or the other, duh).