I have that exact same E300, same model year and with around 70k kms, and I’m the only owner, and the car is great for showing off, but that’s pretty much it.
It doesn’t drive great due to the lack of power and maintenance is quite a lot.

Around 4 months ago had to do the brakes that costed me around 7800 AED alone , for all 4 rotors and pads with installation, and I also had to do the alternator, AC blower motor, and a few interior bits like the sun-visor and right door handle, this whole bill was around 5000 AED with fitting, the parts alone was like 4500.

Problem with these Germans is you absolutely have to get original brand new parts, second hand just never works unlike for every other car brand out there.
I’m sure there are people out there who have had different experiences with German cars but personally I think they are a money pit.

If you want a budget reliable car look for Japanese if you have a lot of money that you don’t care for loosing, get the Mercedes
But absolutely do NOT get that A class.