You can save a lot of money and stay in a decent hotel if you look for something in Yaumatei, just North of Jordan MTR station. Look at www.asiatravel.com for details.

I see there are a couple of inexpensive places listed that are (generally) in the Causeway Bay area, Hong Kong side. This is a nice area, too, with Victoria Park close by.

Just for cost calibration, I see that even dirt cheap Noble Hostel is now HK$200 and HK$300. At the 4* level, you will definitely both pay and probably be disappointed.