Yes, it is worth looking at, the 190e is a safe and reliable car, 5k seems to be a fair price if the car is in very good condition, make sure the aircondition works, if the aircondition does not work, it probably won't be worth buying unless they give a large discount for this problem, make sure you check for oil leaks, one good way to do this is to look at the spot where the car is always parked.

Start the car and let it run for about 20 minutes, listen to it idle, vibrations or engine shaking are not good signs.

The best thing to do in my opinion is to have a mechanic check out the car. Trust me, don't buy the car unless you can have a mechanic check it out, ask for records also. Most mechanics charge between $65-$100 for a pre purchase inspection and it's worth it even if you have to walk away from the car.

The 190e has virtually no space to sit comfortably in the back so you might want to consider your needs based on this, the 300e has more space. You might be able to get a 1990-1991 300e with over a 100k miles for about 7k. Don't let the high miles scare you, if the car has been well taken care of, you can drive this car forever.

Good luck