SLK/R170: Buying 2003 SLK 230

Car has all the option except no Xenon lights and sport package. It has seat heater and power seats.
Owner is asking for $5500. I will offer $4000.
VIN is WDBKK49F23F274298 with built date is July 2002.
Car looks average from outside and don't have any dent or ding. Inside is more wear.
Is $4000 good price??
I own two of W210 and has been enjoying them for last 7 years. This will be my first SLK convertible.
Please can some one tell me list of issue with 2003 SLK 230? Your help will be greatly appreciated.




