For this, we would suggest you walk into the nearest service centres as they will be better people to assist you. You can click on the following link to see the details of the nearest service centres and selecting your city accordingly - Service centre.
Offers and discounts are provided by the brand and it may also vary according to the city, brand, and model. Click on the link to check the current month offers (if any): https://www.cardekho.com/car-deals-discount-offers.htm There are scenarios wherein dealers also give attractive deals to their customers. Click on the link to check dealership details: Car Showrooms
The difference between Mercedes Benz E-Class E200 and E220 is that E200 comes equipped with Rear Curtain, steering mounted touchpad to start things or off, etc. Moreover, you can click on the link to see the complete comparison details.