There's a difference between tours such as "Keys to the Kingdom" or "Behind the Seeds" and such and what I believe you're talking about where you hire an actual tour guide to usher you through the park. That is called
VIP Tour Guide Services.
Experience the VIP treatment as only Disney can provide. Our VIP Tour Services team customizes your vacation so you spend your time playing, not planning. From the moment you arrive, your personal VIP Guide is there to take care of everything - from creating your ideal itinerary to getting you the best seats in the house for live shows, parades and nighttime spectaculars. Prepare to be pampered with a Disney VIP Tour.
Duration: 6 hours minimum
Cost: $175.00 to $315.00 per hour per party
Theme Park admission is required.
All prices include tax. Program itinerary, content and prices are subject to change without notice.
Cancellation Policy: If your plans change, please be sure to cancel your VIP Tour 48 hours in advance. VIP Tours cancelled with less than 48 hours advance notice are subject to a fee equal to 2 hours at the booked rate per VIP Tour Guide.
For more information about any of these tours or to make the necessary arrangements, call 407-560-4033.
It's VERY expensive (something like $200/hr I believe) with something like a six-hour minimum purchase. You do NOT get "front of the line" passes but they will coordinate to get Fastpasses for the group. It's suited for people who want everything done for them, without any need to plan or learn their way around the park.
It's not exactly a true family vacation experience most people want when they go to WDW.