OP - Really depends on where you want to stay. Renting DVC points will be guaranteed to be cheaper than villa rack rates, pretty much always be cheaper than deluxe rates, may or may not be cheaper than moderate, and will probably cost more than value. Looking at rates for late Sept, All Star Movies is less than $134 per night. Caribbean Beach is less than $226 per night for that same time period, AKL $342/$423 (depending on exact dates), and AKLV Studio at Kidani $421/$476. Those were pulled from the rack rates listed on MouseSavers for the cheapest cat, with non villas showing weekend prices. David's DVC rentals will cost you $14 per point minimum with a $2 surcharge depending on resort. A studio at OKW would be 13 points per night, and one at SSR would be 15 per night. (Once again, dealing with just weekend prices here, weekdays are less). A 1BR villa would be 26 and 29 respectively at OKW/SSR. So 13x$14= $182, 15x$14= $210, 26x$14= $364, 29X$14= $406. So both studio prices are definitely more than All Stars, slightly less than Caribbean Beach, and well less than AKL/AKLV rack. The 1BR costs more in most cases, but will include a full kitchen as well as washer dryer. Remember, the studios only come with one bed, so people 3&4 sleep on a pullout, no washer/dryer and only have a kitchenette. Not going to run all the numbers, but that should give you an idea on how to compare. David's has a cost calculator on their site, so you can easily select your dates and see the costs for the different resorts, then just compare that to the numbers the WDW site returns for a regular room. Other rental companies may charge less, and most rentals direct from owners cost less, but come with higher risk. PP's already mentioned things like thinking about potential free dining or even just a room discount, so keep those in mind when looking at numbers.
