Baco, the number for my dealer (Freeman Mazda) is (972)438-2121.
Wayne Sharp handles the internet sales and he's the one with that maintains the site that listed it for about $19K just a few weeks ago. I personally find him to not be particularly personable, and Doyce Jouett is my salesman, I don't know if he'd know much about the going deals on the MS Miatas though.
The DFW area is great for Mazda deals, even if you just want to pit one dealer against another across the country. There are 8 dealerships here within less than 40 miles and the competition is extremely high.