The trouble with the prices is you have nothing to compare them to as there are no independant food outlets in the parks/village. To be honest, the prices at DLRP are no worse than any other european theme resort. Try feeding a family of four at
Legoland Windsor or Alton Towers for example.
Where there is no outside competition for customers the prices will always be high. IF DLRP allowed external vendors on the site, they wouldnt be so keen on theming (to keep prices down), DLRP would have to lower prices to compete so their facilities would suffer and you'd get a downward spiral resulting in the absolute rubbish that UK theme parks offer.
You simply
HAVE to take food prices into account
when you budget your holiday. For example, we are staying at the Cheyenne instead of the NPB and this allows us a good restaurant meal every night with the price difference. There is enough info on the multitude of websites for DLRP so that no-one needs to be surprised when they arrive. Yes, £45 for burger & chips IS expensive, but you have the choice of not paying it if you dont want to. There are enough places at DLRP where you can get meals at (relatively) reasonable prices.