Phuket offers a wide variety of accommodations, rates start at around 50 Baht for a bed in a dormitory, guesthouses from 250 Baht per night, up to 20,000 Baht and more per night for a luxury suite in a big 5 star hotel or a small boutique hotel.
The top end among the luxury resorts is Amanpuri and The Chedi on Panasea beach. The elegant thatched suite huts and exclusive setting will impress even the worldliest connoisseur. If you can afford it. Rates starts from 750 US$ up to 18000 US$/night for a 6 bedroom villa with ocean view.
Rates differ between the seasons and you will most probably get big discounts during the monsoon season (April-November).