S.S.
In Dallas, that's unreasonable. The market rate there for an infant is $200 a week or $50 a day from what I understand. You might have better luck finding someone to trade childcare with - but then you run into issues of different parenting styles, etc.
You can search licensed providers in your area at http://www.dfps.state.tx.us/Child_Care/Search_Texas_Child... and then call and find out what they charge / etc. You can also view their previous inspections for any deficiencies.
In Wichita Falls, you can get a full time infant spot for $125 a week, or $30 a day - in centers. In homes, it's closer to $100 a week.
Good luck
S.