Found this on Mouseplanet:
Believe it or not, the tax rates at the various resorts various across Walt Disney World. In all cases, the state sales tax is 6% and the state resort tax is 5%. However, in Osceola County (the Southern part of WDW), there's an additional 1% county sales tax. What that boils down to is this:
The All Star Resorts have a resort tax of 5%, and a combined sales tax of 7%. Your room, then, will be taxed at 12% and purchases (sundries and souvenirs) will be taxed at 7%.
Purchases at the Wide World of Sports would also be hit with the 7% sales tax.
All other WDW resorts and retail locations have a resort tax of 5% and a sales tax of 6%. Your room, then, at any other WDW resort, will be taxed at 11% and purchases at 6%.
If you stay offsite, just keep in mind that you'll be hit with that slightly higher rate if you stay in Osceola County (along SR-192, Irlo Bronson Memorial Highway
I think they should just do like all civilised places do and add it onto the price straight away. ... same as service charge & tips
JJ