After six months in Australia, I have seen Mexico as a cheaper country. The cost of life is less expensive than in France. it is like half price. My budget was around 900 euros per month. I had also some economies to travel. 1 euros corresponds at 20 Mexican pesos.
For my accommodation, I lived in a shared-flat with Margaux, Océane and Odélia, 3 others ipagiennes. I had my own room and bathroom. The apartment was situated in Roma Norte. It was a very safe and quiet neighbourhoods with lots of shops, restaurants, gardens and nightclubs. My rent was 7500 pesos per month. Gas, water, Wi-Fi included. To go to my school, it was 1 or 2 hour by drive, it depended of the traffic. Usually, we used Uber. Because it's more recommended for foreign people. More safe than taxi or common transportation. We shared the price in 3 with others students.
About the food, the price depends of what type of product you consume. For example, fruits and vegetables are cheaper than in France, but the chocolate or famous brands were more expensive. Do to my food shopping, I went to Soriana or Sumesa. They are supermarket brands in Mexico. I had also the habit to go to a traditional market every Sunday morning to buy fresh and local products.
When i arrived in Mexico, I took a mobile plan by AT&T brand for 300 pesos per month. I had unlimited messaging and calling in Mexico and 2GB of Internet data. The only problem with this company was for the network. I couldn't use my phone in every places in the country. I recommend for the next exchange students in Mexico to take a telephone subscription by Telcel. The bigger brand in Mexico, like Orange in France.
The bigger part of my budget was for travel. I spent lots of money to discover this country but I don't have any regrets! Mexico is a amazing country and I did unique experiences. I went to Puerto Escondido, Xochimilco, Teotihuacan, Taxco, Puerto Vallarta, Acapulco, Yucatan, Chiapas, Baja California, Valle de Bravo, etc.