A study published in the Journal of Sensory Studies found that the amount diners paid for an all-you-can-eat (AYCE) buffet determined how good they thought the food tasted. Those who paid $4 for an Italian lunch buffet thought the pizza was “less tasty, less satisfactory and less enjoyable” than did those who paid $8 for the same buffet. What’s more, those who paid only $4 reported that the more they ate, the worse the food tasted, whereas those who paid $8 had no such sense of diminishing enjoyment.
Admittedly, it’s not about taste so much as satisfaction.
Vegas buffets operate at a loss. The intention of these buffets are to get you go to or stay at the casino. Presumably you are paying less for higher quality food (at least at this particular group of casinos).