Disney does not advertise, as I stated, so you have no choice but to call them for the prices and compare that way. Once in awhile, I've got a CM who actually was able to figure out when the buffet surcharge dates are, so you might get lucky and be able to get the actual dates for when the surcharges are in effect. You could see what last year's dates were, but this year, they changed dates by weeks (summer), so not sure if this will be entirely accurate, but it will give you an idea. I'm pretty sure that all of Christmas/NYE is part of buffet surcharge for sure.
It is not all TS restaurants - it is buffets and all you care to eat places such as: Chef Mickey's, CRT, Boma, Garden Grill, etc.
$4.00/adult + tax and $2.00/child + tax
HTH, Tiger