Need help with purchase decision

[2003chevcav]

I am currently interested in a 1998 Cadillac DeVille. It has 156,000 kms on it, it is in top notch condition. No rust, new tires, transmission shifts very smoothly, and it is very clean inside. The ride is very nice also. My questions:

1) Is 156,000 kms a lot for this car?
2) The asking price is $8800.00 (Canadian). Is this reasonable?
3) Has anyone had any experience with this a '98 Caddy DeVille?
4) I hear the oil consumption on the Northstar V-8 is high. is this ture? If so, why? is it normal?
5) I actually read that the gas mileage is decent. Does the engine have cylinder deactivation like the older caddy's did?
6) Is this model reliable?

I need some help in making my decision. This car is great, but as with every used car there is a risk since there is no warranty left. Can anyone give me their feedback?