As a developed and popular tourist destination, Sydney is not short on accommodation and whatever your budget you are sure to find hotels The Rocks Sydney by researching pricing on the internet.
If you have cash to splash, there is no shortage of luxurious - and expensive - hotels such as the high-end Park Hyatt Sydney which enjoys a stunning location at The Rocks or the Quay Grand Suites, both overlooking spectacular Sydney Harbour. If you are not willing to pay that much there are still many 4 and 5 star hotels in a reasonable price bracket, some also with Harbour Views such as the Marriott Sydney Harbour or the Crowne Plaza Darling Harbour.
There are plenty of hotels, too, to be found under 150 or even 100 Australian Dollars per night. They will not be luxurious but most are clean, comfortable, functional and friendly!
For those on a really tight budget, there is also plenty of choice, from just 20 Australian Dollars per night. Hostels such as the Asylum or the Boomerang Backpackers Hostel (great names both of them!) provide cheap and cheerful accommodation with shared facilities. Most are great value; just do your research beforehand to weed out the good from the bad.
However much you want to spend on your hotel in Sydney, you can be sure of finding something to suit every budget.