Pretty sure this is a regular discussion item and can be debated all day long.
They are expensive especially when you're paying for a Disney adult buffet meal for a 12 year old that eats less food than a 2 year old

At any rate, the dining plan for us has never really made sense since we just don't eat enough food or really care for some of the restaurants where the dining plan gets you more bang for your buck. Overall, all the food prices have increased at WDW. I don't know the current rate for some buffets, but we did Crystal Palace on our last November visit and it was well over $240 for 4, I think $59pp + gratuity. That meal is in no way worth $240 even with the characters and incredible location.
We like Boma and Ohana for breakfast, still a little pricey but much more reasonable for what you get and overall quality. 1900 Park Fare is IMO a little better in terms of food variety than Crystal Palace and the characters are much more enjoyable but still not sure it's worth the $$$. Bottom line, Disney raises its prices and I still very gladly hand them our money LOL!!