the best values are the wolfgang puck expresses...and they are really sit-downs...even though you order up front.
beyond that...other than the mentioned plaza...disney all but eliminated the "low priced" sit-downs in the last ten years....but there used to be some great ones...including
Kona, GF Cafe, The concourse steakhouse (which was an excellent meal/deal), boatwrights, olivia's (was just the best till they had to yutz with it), whispering canyon, and a few others...
i long for those days where i could get a 4.95 conch chowder and a 12.99 cuban sandwich at olivias...and a 5 dollar key lime pie. There was nothing better.