http://www.marriott.com/hotels/hotel-rooms/okamc-okinawa-marriott-resort-and-spa); and we stayed during 25 Dec to 29 Dec for 5D4N for HKD8140+540(tax) each adult. While my friend who stayed during 27 Dec to 30 Dec for 4D3N for HKD 6920 + 540(tax) for each adult.
BTW, if you wanna drive in Okinawa, OTS will be one of the cheapest car rental in Okinawa.
Good luck and Have fun. =)