If my stay is for seven days, I always rent from an owner rather than do retail to save $. I usually use TUG2.net classified ads section which you can access without joining or Redweek.com (mentioned by previous poster). On Redweek.com you can sign in as a guest to look for rentals, but to actually contact an owner, you will need to join ($15 per year). I always just sign in as a guest and join that year if I see a rental I am interested in.
There are usually tons of rentals for the Sheraton Vistana Resort and Cypress Pointe with pretty good prices. These are the properties I've rented most recently.
For a shorter stay, I saw some really good retail prices for Cypress Pointe on Expedia (not as good as an owner rental, but excellent for retail // less than most hotel rooms). It was one of those Expedia specials. These were just for one and two bedrooms there, and I usually like to go for a three bedroom at this resort, as the second bedroom just has two twins and is quite small.
In Dec. 2008, I got the Sheraton Vistana Fountains (newely renovated 2 bedroom condo) for $1000 for the week. It was great. Prices are often lower for less popular weeks too. I've seen quite a few three bedroom rentals at Cypress Point (people have floating weeks there, so it's usually easy to get the week you want) for $1100 or $1200 on the sites listed. For our spring break week, I even saw someone who was offering their three bedroom for $799.
You'll find some Marriotts on these rental sites too. They usually rent for a little higher, but take a peek. I one time wanted a springbreak week at the Marriott in Palm Beach shores, but I thought the price the people wanted was was too high -- like $250 a night, sure retail was $480 (but you should pay considerably less for an owner rental). I told them I'd pay $1200 for their week. We needed two units, and that's what I got the other one for. They said no way. I kept everything friendly, and said, well keep my offer in mind just in case you can't rent it and change your mind. If you can get a higher price, though, or want to use your unit before renting it for $1200, go for it. And sure enough, they emailed me four months later, and I got my $1200 price.
