Is it worth buying a Mercedes or a BMW that has over 100,000 miles. I've noticed they are very cheap.
Yes, they are very cheap because they are endless money pits when they are that old. Don’t buy them. If you get them from a relative for free, then yes, you may want to take that off their hands. I’ve had a few customers over the years who inherited a Mercedes for nothing and I tell them "you’ve got it for nothing, drive it and I’ll maintain it." And I’m honest and say as soon as I see something big going on on the front end then sell it and get rid of it.
If you are going to need an engine or transmission job done, that is going to cost thousands so get rid of it. But the reason they are so cheap is because they are endless money pits. They are over-engineered. When I was a kid, those Mercedes 300D diesels could go half a million miles. They were pretty much trouble free. Not any more. They are over-engineered junk these days. They aren’t made nearly as well as they were in the past. Most of those in the United States aren’t even made in Germany. So you’re just paying for the name and they aren’t worth it. And if you buy one really cheap or free, go ahead. But don’t put much money because they will bankrupt you.