For a 1 bedroom, checking in on a Friday in May, 2008 and then out on a Sunday (9 nights later), you would need anywhere from 292 points (OKW) to 364 points (BCV, VWL, BWV Preferred). BWV Standard and SSR are somewhere in between those amounts.
Multiply the number of points by the price per point - at $12 per point, it would run between $3504 and $4368 (or $389-$485 per night).
FWIW, the Friday and Saturday nights are much more expensive than the other nights. Since you want two weekends, you may be better off paying cash for your trip, especially if you are able to get a discount of some kind. WDWTC/CRO does not charge more for the weekend nights.
For comparison, 5 weeknights in May would range from 100 points to 140 points. At $12 per point, your nightly cost would be $240 - $336 per night.
There is no tax on DVC points rentals. A 1 bedroom sleeps 4 plus an infant under the age of 3. A portable crib (Pac 'n Play) is provided for the infant.