If you are experienced at cooking for a large group, you have the refrigerator space to store the food before the event, and this won’t cause you a lot of stress, then I say go for it! The menu sounds great and I’d LOVE to show up to a grad party and be served homemade food (and my teens wouldn’t notice if the food is homemade, from Costco, or a fancy caterer, they’d just care if it tastes good).
That said, I think this will be a lot of work for you. You can buy prepared foods at Costco or even a full “catered” buffet from a place like California Tortilla for a lot less than $10k or even $1k

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