Texas is a non-disclosure state, so the public records won't be of any help as far as records of prior sale price. Your best best is contact a local Realtor who can access the info for you in a matter of minutes.
You can first start by doing a search for the property address on the web. The local court house will have this info as well. Maybe one of the fastest ways is to ask a local Realtor if they can pull up the tax info and it should show the past selling history. I hope this helps with your search.