I don't know how my way compares with anyone else's, but I know how it compares with professional services. Here's an example: (a really big well known company in/from Chicago)
Vegetable Tray (16” Tray Serves 18-20) $34.99
Crunchy baby carrots, tasty grape tomatoes, cucumber sticks, broccoli, celery sticks, red peppers, and cauliflower. Ranch dip.
Cheese and Sausage Cube Tray (12” Tray Serves 12-15) $34.99
Cheddar, Swiss, and Mozzarella cheeses, plus Genoa Salami, Cotto Salami, and flavorful Pepperoni with a Dijon Mustard dip.
Fresh Fruit Tray (16” Tray Serves 18-20) $44.98
We select the freshest fruit of the season. Served with Caramel Apple and Cream Cheese dip.
Hot Wings (8-10 appetizer size portions) $24.99
Buffalo style wings covered in hot sauce, with just the right blend of spices to give them a true “buffalo wings” flavor. Side of ranch dressing.
BBQ Glazed Wings (8-10 appetizer size portions) $24.99
These wings have a unique blend of sweet and tangy flavors to create a mouthwatering treat. Side of ranch dressing.
Chicken Tenders (8-10 appetizer size portions) $19.99
Twenty strips of breaded chicken. Available with honey mustard, ranch, or BBQ sauce.
OK. I'm not sayin', I'm just sayin. That's not the stuff that I make and serve, but that's what I've got to compete with. As for your "cooking demo", charge what the market will bear, just be ready to pull off one heck of a good job in your client's eyes if you're pricey.