So the printer has only actually printed for 862 hours which is better than you thought. The first print head, which I believe is the Cyan/Black head, has been changed recently and only has about 3.3 million fires per channel. So it's basically brand new. The 2nd head which is the yellow/magenta head is older and has about 2.4 - 3.3 billion fires which is about half the life span of these heads. Still pretty good for a used machine. It looks like at some point they were having issues with the scan motor system which is why there are 44 scan motor errors. This was most likely a bad encoder strip or sensor as the motor was never changed and motors almost never go bad in my experience. Looks like the machine is in good condition on paper. I would definitely go check it out in person to make sure it isn't making a bunch of weird noises or just looks really dirty.
I forgot to mention, the machine is a little over 7 years old based on the sleep time. So in 7 years the owner only printed with it for a total of about 36 days. This machine is old but barely used. The fact that they had to change the 1st head at about 2 billion fires tells me this machine basically sat around not being used every day and the head dried out. It should be a good buy if the price is right.