Freddie,

If you're in the US, that'll be a 91 560SEL. If you want a newer car, be ready to spend 2-3x the cost of a good 91 560SEL for a good and hopefully Starmarked 95-96 S500. Even better would be a 97-99 S500 at 3-5x the cost of a 91. The 97-99 gives you more safety features among other things. You can get a 92 500SEL for the price of a good 91 560SEL but think about what you'll be getting if you get what you pay for.

Sixto
91 300SE
87 300SDL
83 300SD