The cost of certain ingredients have taken a sharp upwards turn - it's not surprising to see the cost of many items going up.
Oh, and the shrinking size is an old food industry trick - you make a smaller size and then don't increase the price (or by a minimal amount) - most people don't notice.
Think about coffee - you used to get a 1 lb package for $XX, then they changed the package size (smaller) but you were still only paying $XX. Many people never noticed the change.