I do not think you will find a 4* hotel in Sydney for US$100.00. You might try the Holiday Inn, Darling Harbour. I always use Price Line and have never been disappointed. Sydney is a size that not matter where you saty you can walk anywhere. Fantastic city! Good luck on a hotel website for $100.00. I have gotten a hotel through PL for US$100.00. If you find it on a regular website, please, post it in here!