I am no stranger to Mercedes Benz, having owned one or another now for about 20 years. My first Mercedes was a 300SEL. The same W126 chassis as the 500SE AMG I am reviewing. That being said, I purchased this vehicle for nostalgia value, both in memory of my first Mercedes, and the desire as a young boy in the 1980s to own an AMG Mercedes.
That being said, this documented vehicle is not for the faint hearted. I had the transmission rebuilt and an assortment of mechanical work done at a Mercedes independent shop. I am not sure how much it came to, but in the several thousands. I have also being restoring it to its former glory. It cost $80,000 new in 1984, making it one of the most expensive vehicles of its time. It is currently running magnificently.
Acceleration - amazing.
Power - amazing.
Looks... well you get the idea.
I own two other Mercedes. One is my winter vehicle and a highly modified Porsche 911 twin turbo. I have barely driven the Porsche; I enjoy the 500SE so much more. It makes no sense, but if you drive one, you will understand. Car enthusiasts speak of soul. This car has it. If you are looking for a daily driver, I would not rule out this chassis. It is one of the best Mercedes has made. My 300SEL served me well for years.
I caution you on the following. As cheap as these vehicles have become, the newer owners seem to be unwilling to keep up on the maintenance. Parts can be expensive. Gas mileage... maybe 17 MPG... more likely less than 15. If you have a desire to own one, have a pre-purchase inspection done at a Mercedes independent shop. I would check the Mercedes forums to find one that knows the chassis you are looking at.
Mercedes Benz are great vehicles if they are cared for and maintained according to the specifications. They are not cheap to own, but will serve you well in the long run.