You need to give specifics.

Are those prices for first-class or coach?

WHEN are you going? (e.g. around Christmas, 4th of July, etc.)

Did you price connecting to see if it would be less than nonstop? (Although, I don't think there would be a connecting from Cleveland to Houston, but doesn't hurt to check.)

And how far away is your travel date?

If you are going at a non-holiday time and you are going coach and your travel date is more than a month away, I honestly would not pay more than $250-300 per ticket.