Im not sure about the Polaris’s but normally when a 850 doo goes down 5k won’t take care of it. I would think if you were easy on the machine it would make it to 10000 kms but I wouldn’t bet on it.
I wouldn’t spend that much for extended warranty
my understanding is the 650 and 850s are reliable
I would never keep a sled beyond 6000 miles / 10,000 kms anyway myself
$5000 seems like quite a lot for extra protection