Over the last year the median price in Chino Hills has gone from $611,000 to $640,000. (October 2006 - December 2007). I don't anticipate there being a drop of 20% this year, however there more than likely will be a drop of some sort. You may be able to find something that is a great deal already, and then negotiate even further downward from there rather than waiting for the market to hit "rock bottom" or drop 20%.
For those buyers that are "waiting", I always ask, how will you know when the market has hit "rock bottom" and when it has hit "rock bottom", do you think the sellers will know also? Furthermore, when the sellers find out, do you think you will still have the same negotiating power that you do right now?
It is hard to say what to do, and when to do it, but the best advice I can give you is to evaluate your financial situation, find out what you can afford and are willing to spend on a monthly basis and then go out and negotiate the best possible price for the home of your choice.
I hope this has helped, please let me know if I might be of any more assistance to you. You can also access any of the homes that are on the MLS via my website below.
Prudential California Realty