You can take bus No.122 from Beijing Railway Station to Beijing West Railway Station, just walk east from the overpass on the big screen of Beijing Railway Station (there are many bus stops there, the first one is probably No.122) and go directly to the South Square of Beijing West Railway Station. When you get off the bus, you can see the Dafang Hotel, which is a four-star hotel. Its Chinese food business hours are from 11: to 2: and from 5: to 5: in the afternoon. The per capita consumption is almost the same as what you asked, and it is convenient to catch the train near the West Railway Station. There are many kinds of food there, such as sweet, sour, salty, spicy and light.

ps: It takes me almost an hour to get to the West Railway Station by taking the 122.