1. The rent is about 200~300, which should be about the same. It's hard for you to live too cheaply.
I am still a student, so I can't tell you how much I earn every month. However, judging from the recruitment information in the newspaper, 1800~2200 is still in a relatively normal range.
3. If it is 1800, 250 rent will be deducted. If you eat it every morning, noon and evening, it is estimated that it is about 9 yuan, and then 9*30=270 is deducted, leaving 1280. Even if there are tolls, utilities and petty corruption, you can still save 1000 yuan a month.
I hope it helps you.