Vickee,
Not very expensive, just the diving & ballooning expensive, $1xxx, you can delete that, diving: better have licence b4 going; ballooning: very early in the morning... you can buy a "lonely planet" to plan your trip, can be very cheap, this book provide all info, from cheap to expensive... We've stayed in a youth hostel, say HK $2xx for two per night... car rental per day is about $60 Aud... 但好花精神去plan行程..