How much would a party for 30 to 50 people cost?

I'd like to have tacos, nachos, quesadillas, pizza, soda, lemonade and water. I'm not sure how much this will cost.... I know that flour tortillas are $1.69 per bag of 8, and cheese is $1.69 for 16oz.. soda is .89 a bottle, and otherwise, I really don't know.. any guesses?