Mercedes are durable cars and tend to last a very long time.

However, those of recent vintage are complex machines, particularly with regard to electronics, and can be troublesome.  120K miles is also enough miles that there can be many maintenance items needing attention.  A lot depends on how well the car was cared for over its life.  It's also worth noting that Mercedes service tends to be costly.

Frankly, if avoiding expenses is a primary goal, the money would be better spent on a much more recent Toyota or Honda.  They wouldn't be as much fun but they will probably be more dependable.  Probably not what you want to hear, but there it is

My ML430 has 172,000 miles on it and it runs superb! That said, Marsden is right about the maintenance thing. You can buy this car and it be a dog. These early ML's were a hit and miss on quality and while mine has original engine and tranny, there are just as many or more that don't. I think 10k is WAY too much to pay. You can pick up a 99 ML430 with that many miles for between $6,500 to $8,000. I gave $14,250 for mine nearly 4 years ago with 90+k on it. It has not been without trouble but I've been quite lucky compared to others. I take extremely good care of it.

These are the issues you need to consider on this vehicle:

1. Transmission service, if not performed, is well overdue. Do not believe this 'sealed for life' crap. They do need fluid and filter changes about every 60k miles or so.

2. Cooling system will need servicing as well, if not already done.

3. Mass Air Flow sensors are bad to crap out ($260.00 part and 5 min. of your time) as well as Crank Position Sensors and EGR valves.

4. Fuel Filter AND modified fuel lines kit will have to be done if not already performed. The 'old' fuel filter isn't available and you will have to spend $75.00 for the line kit and the labor to install. Clogged fuel filters will burn up your fuel pump.

5. If you have a panoramic roof, they are troublesome as well. They almost always eventually jam and repairs are expensive, if parts are available.

6. Recall items such as the power steering hose and harmonic balancer should have already been done.

You can check to see if the dealer performed all these services by requesting a Vehicle Master Inquiry. A dealer who wants your service business will do this free of charge.

Hope this helps!