They're pretty reasonable. All i've gotten from them is a lugnut/locker set, some wiring and misc fittings. My buddy got an SCT tuner for his powerstroke from them with 3 custom settings for $350, which he said was the cheapest he found.
btw, Laurel is about 40 mins from Mt. Airy.
I do all my own work but, I had these guys do my SCT chip and dyno tune. Good guys, I had a new 190lb in tank pump sitting in the car and they installed it for free. I also went back for a retune- free. They don't bull**** you either. Torey, is the guy who took care of me. A few other guys from Andrews AFB use them with no compliants that I've heard of...
Check out superstallions too as there are a lot of MD guys on there. Their yearly event is coming up soon too at cecil. If I get my rollbar done soon I'll be there. You may also want to check out the NVMC northern virginia mustang club for advise on where to go too. SGS isn't too far from MD depending on where your at.