Renting a home or condo offsite can can prove to be a significant money saving move. If you have more than 2 people in your party I'd recommend it every time. In addition to the cost saving for a place to sleep, the savings on meals is a huge consideration for us.
I prefer to deal directly with the owner and I'm not afraid to ask for a great deal, especially in this economy. Now, keep in mind that we only go to WDW off-season, but the rates I get for a lovely 6 bedroom, 4 bath home are the equivalent of 1 mid range hotel room. This year there appears to be a larger percentage of owners who will discount rates to keep from having too many vacant weeks.
Having stayed at this property 4 times we can highly recommend you take a look at
http://www.sjsvillas.com it's a great location and their local manager does a fantastic job at upkeep.
As you look for the best place for your vacation we suggest you make a list of the amenities you must have (for us a king size bed in the master, full size washer/dryer) and those you would like to have (nice view from the pool/lanai), then begin your search. We were looking for a 3 or 4 bedroom home when we found this 6 bedroom at the best price. It didn't have one feature we really wanted, a BBQ grill, but the owner arranged to bring one in for us.
There are so many properties available you should be able to find just what you want at a great price. Good luck in your search and let us know what you thought about your offsite choice.