Buying a home is one of the most important purchases that you can make. You definitely want to feel comfortable with the price you are paying. If you are working with a Realtor (which I highly recommend), have them pull comparables for you of similar homes that have sold. This might calm your nerves and reassure you that you are paying a fair price.

As far as prices and interest rates falling, 5.75% is an outstanding rate and home prices, for the most part, are beginning to be more stable. If you wait, you risk that chance of securing a loan, as we do not know what types of loans will be available in the future. Good luck!!

House prices are holding steady in most areas.
I actually expect prices to go up in 2009....both in real terms and interest rates as well.
There are lots of micro markets in DFW area so not sure exactly where you want to live. Some will likely contiune to increase where there are good demand generators and some of the outlying markets may fall.
Remember though we are still working through the risk based price adjustments on interest rates. If interest rates even go up just slightly that could wipe out any savings you can get on price pretty quickly.
Also raw material costs seem to be rising so that same house you want to build this year may cost even more to build next year.
What does your realtor say?
Depending on your contract you may not be able to just walk away and loose the deposit.
With all that said....no one can predict future prices, interest rates, loan availability, loan requirements, etc.
I just don't think you can time the market.....just too many variables.
If you are ready to buy.....do it now.

Zoomi
You situation is not uncommon. I would suggest a couple of steps:
Read your contract. IF you need legal advice, consult an attorney because this is not legal advice.

If you like the home and the area, how about re-negotiating the price? If you have a Realtor representing you have them check for the sales of comparable homes.

Good luck.

Zoomi,
I asume that you are not working with a REALTOR on this deal.
You should give us a little more details on the contract you are in with the builder.
Is there an option period, have you done inspections etc.?
You might still consider talking to a realtor to get a CMA for the area, even that you are already in a binding agreement with the builder.
The builder typicaly will not pay a comission to the realtor anymore and you might have to pay the comission for the realtor advice yourself but it might still be worth your money to do this.

Good luck
Martinas