"With the tax credit expiring and some percived uncertainy in the market, why should we buy now?"

There are excellent interest rates on mortgages currently, which will make payments lower. We haven’t seen interest rates like this for 40 years and may not again.

There are fewer buyers in the marketplace and the benefit is there is less competition for the best homes.

Lower buying activity in the marketplace causes lower prices, which translates to better buying opportunities.

Sellers may be more willing to negotiate not just on price but also on other things such as paid closing costs.

People were still buying homes in the early 80’s when interest rates were 18% for FHA and 7 points. Buying a home, even at high interest rates was still a better alternative than renting. 

It is a great time to move up if you have equity in your current home.  With the low rates available, you can often afford a larger home at close to the same payment they are currently making.