I know this is an old post, and I also get this question a lot.
Besides the tight market, the State of Texas frowns on the old "Lease to Own" because there are few protections for the would be tenant buyer. If there is a mortgage on the property, the mortgage company probably does not allow this, either.
There may be other options, talk to me or another REALTOR to see what the best options are. Credit repair can often be faster than you think!