I recently read in the September/October 2006 issue of Texas Realtor magazine that Texas' average credit score ranks 50th among U.S. states.  The average credit score in Texas is 648.  In South Dakota, the highest ranked state, the average credit score is 711.  The 'brief' in the Texas Realtor magazine states that a person with a top credit score might pay $231 less per month than a person with a poot credit score based on a $216,000 mortgage.  I don't know why they chose $216,000 but it certainly demonstrates how important credit scores are to the lending process and how much these scores can impact the real estate market in Texas. 

If you are keeping track, the $231 per month is equivalent to $2,772 per year or, over the life of a 30 years mortgage, $83,160.  It's also said that an extra $6/month in mortgage payment buys you approximately $1,000 more house.  That's $38,500 more of a home that would be available to someone with a better credit score at the same payment. 

Texas Realtor magazine cited Experian and "myFico savings example using a 30 year mortgage with prevailing national rates in August 2006"