An Army/Navy surplus store is the only place that comes to mind.
I've noticed over the years that used BDUs seem to be less and less common, but there are usually some around. The prices on the new ones also seem to have risen quite a bit at the same stores. Not to mention, several surplus store that I went to in the past have gone out of business, or changed to yuppie gear stores.
Where in Alabama are you?
The Command Post (205-663-5678) in Pelham might have some, but I haven't been there in years, and there is a Army/Navy store (205-425-6995?? I called to verify that #, but didn't get an answer) in Bessemer that has always had a decent variety of new and used BDUs.
There's another one, I think, in Bynum, over near Anniston. Real nice folks, and I bought a bunch of stuff from them, but it's been five years since I was out that way. If I find their card, I'll post their phone #. One of those places I can drive straight to, but can't tell you how to get to
