I have owned three . There are four trim levels for that car . Does it have leather ? They can get 30 mpg on cruise at 60 on interstate driving and avg around 20 in town . If it is the Ls or the rarer LsUltimate ? Was it keep in a Garage ? Have you ran the vin for previous damage ? Even though it has low miles,every thing on that car is 11 years old . I would bet it has the original tires which might look new,but would need to be replaced . The brake fluid,the power steering fluid,and the coolant all need to be changed.I went moble1 oil on everything when it first came out and would do so on this car . As people age they tend to reject information that doesn't seem to correlate to what they learned.
The fluids contaminate by condensation over 11 years,the tires dry rot in 5~8 years . You can change the power steering fluid with a turkey baster(google it) the brakes will look nearly new,but will take a mechanic you trust to bleed down and replace with fresh new fluid.The engine oil if it was never changed,needs to be changed , that 4.6 v8 uses 5w-20w show him this information , the worst thing for any car is not getting run at least once a month,to circulate it's lifes blood so to speak . If it has been garage keep , the paint is perfect and the interior is perfect , I would offer him what he would take . 10k is on the high side , but that car will last you until you are sick of looking at it,plus it rides like a Cadillac has enormous storage and there aren't many cars that are that safe on the highway . It's worth is 7500 , I would start there . A dealer will give him 10 for it , and highball him on the Buick(a very old dealer maneuver) I paid 2500 to 4k for mine , yours will have a like new front end,the shocks tie rods etc. on your car are all like new . Put it on a rack and look under it , should be rust free . Go for it . Ps , you will need a straw hat and drive in the left lane at or below the speed limit ! And your insurance will be cheaper .