It depends on your rent and salary. Judging from your question, it is estimated that you have never done catering. Generally, a meal for 50 people can be cooked by one person. You need a handyman to help at most. I estimate that 15 is the standard of a meal. If you want to buy some dishes, I'm afraid no one dares to help you out of thin air. It is estimated that one main meat, one and a half meat, two vegetarian dishes and one soup should be enough every day. It depends on who you are, student. Office? Workshop worker? Construction workers? If it is well controlled, there will be a maximum profit of 40%. It is estimated that there will be no profit if the construction personnel arrange this. Of course, I have never seen such a high standard construction site. Generally, just stew two pots of steamed bread (the cost of making steamed bread is low). Take a good look at your situation and ask again!