Lisa is planning a vacation and she needs to budget her expenses. She estimates that she will spend $150 per day on accommodation and $50 per day on food. If she plans to stay for 7 days, how much total money will she need for accommodation and food? Additionally, if she has already saved $500 for her trip, how much more money does she need to save? Let's think step by step and output the final answer within \boxed{}.
user