My son has the whole set- we love it! We started out with just the monorail set at first- you get enough track and supports for about a 3 foot circle- and the monorail, of course. It runs on 2AA batteries (in the monorail). You can push the button to hear the monorail give out the messages just like at the parks..."We are coming to the Magic Kingdom, the capitol...." It costs about $40-$50 I think. Maybe $60, but not more than that.
Then, we got Epcot. It was only about $35 and the monorail hooks up to it and goes under the Spaceship Earth.
Then, we got the Contemoporary, Grand Floridian, Wilderness Lodge, and Polynesian Resorts. They were about $35 each, I think.
The last thing we bought was the TTC switch track and station. It allows you to have two "circles" of track and switch tracks. Also, it runs on batteries and it has all of the messages for each hotel and the one in Spanish and English about "Please keep your arms and legs..." or "Mantenganse alajado de los puertos..." So, you can push different control buttons to hear the different messages. It's really cool. I don't remember, but I think it was $45-$50 dollars.
We also purchased extra track pieces- straight and curved- and they were 4 sections and supports for $9.99. So we have a play room that Todd sets this up around the perimeter of the room. We want to put a shelf up high to put it on eventually, but it would have to be kind of wide to accomodate the hotels, etc. (They are fairly large.)
We assembled the hotels, but it wasn't hard.
I hope this helps!