Also keep in mind that neither Southwest nor Independence serve DFW. The best you'll get on WN is to DAL (Love Field), but given the conditions of the Wright Amendment, you'll end up having to connect somewhere (and buy two separate tickets) in order to fly there.

The best way I know to see which airline is serving which route (save for WN) is to do a flexible search on travelocity.com. The search will show which airlines have non-stop, direct, or connecting service on which routes. For TPA-DFW, the only airline that shows anything other than connecting service is AA.

As for the cost of a non-stop vs. a one-stop - AA's lowest bucket prices between $10 and $20 higher than other published fares on the route (all of which will connect somewhere along the way). So the non-stop in this instance may not be the most expensive option, but given that AA is the only non-stop option, I think that might be a little limiting.

Mike