It is a sellers market here. How do I get buyers off the fence to close before Nov 30 and get the tax credit.

I am a broker in Benicia CA an we are seeing 10-20 offers on homes becuase they are such great buys and still so cheap. Buyers keep lowballing them, thinking that they can "steal" a 3 bedroom 2 bath home ( as one could do 9 months ago). They are going to loose the tax credit if they do not get  an offer accepted in the next few weeks as the credit expires Nov 30. This credit is  more than the down payment they will make on an FHA loan. The payment will be less than  rent for most of them. I need suggestins to wake these buyers up...