I think you can ask for one at the front desk in a deluxe resort.
FW cabins and all the DVC resorts have them in all the rooms.
You can go rent a reservations (points) from this site - go find the DVC rental/trade
Sept - OKW should be around $80 a night for a studio. BWV, BCV and VWL around $120 a night for a studio. Sun - thurs only - fri/sat are alot more.