There's no need to buy those expensive vegetables with the cheese sauce mixed in. You can make your own for a lot less and it's healthier, too.

1 oz butter
3 oz grated cheese
3/4 pint milk (powdered milk and canned milk work very well in this)
1 oz flour

Melt the butter over medium heat and cook and stir the flour in it for a few minutes. Whisk in the milk to avoid lumps. Bring to a boil and simmer for a couple of minutes, whisking the entire time.
Add a good pinch of salt and pepper to taste, then stir in the cheese. Taste and season as needed. I love chopped garlic and onion and crumbled fried turkey bacon in this sauce.