hello, the price sounds pretty reasonable, especially since the exterior and interior are immaculate, and the wiring harness and head gasket have already been replaced.

i have the same exact model with 120,000miles on it and am very pleased with the car.

Other things that you might want to research or even replace as preventative maintenance for this particular vehicle:

1. OVP relay (a bad one can leave you stranded, specifically, it can cause a no start issue ) its located behind the battery, if the one in the vehicle is not the new and updated OVP(000 540 6745) replace it.

2. the front suspension: in my opinion , it would probably be best to replace all of the parts minus the shocks, which at your mileage i believe should still be good, mine still are. new ball joints, tie rods, center drag link, and steering damper, along with good shocks will yield an impressively comfortable ride.

At around 112,000miles the driver's side balljoint snapped on my 300e. here's an example: Ball Joint Broke in Half (Pictures)
if you hear a creaking/squeaking from the front end , then its most likely the ball joints are bad, save yourself the headache of having to tow the car home or to a garage and just replace them for piece of mind.

3. as far as the wiring harness problem goes, the same defective wiring is also used in the throttle actuator, so that can also be a potential problem somewhere down the road as well.

otherwise a wonderfull car to both drive and own, i'm sure that you and the misses will enjoy it.

if i think of anything else i'll let you know.
good luck, hope you get it