Ответ:

McDonald's

Hamburger about 50-100 rub, I think cheap

French fries about 60-90rub, cheap too

Milk shake about 120-180rub, cheap

In McDonald's you can eat a lot of cheap food, plus u don't have to wait a long time

I can tell about the american cafe it`s popular not only in America, it`s popular in Russia. It is a  McDonalds. There we can taste burgers, chips (картофель фри, не чипсы), shawarma and nuggets. Prices at McDonalds are normal. Not expensive, and not cheap. A Burger can cost 249 rubles.