I've got the same problem In Tallahassee. There is only one and its not very good.
I get mine off ebay and at gun shows. At the larger gun shows there is just about always someone selling ammoc ans. SOmetime they are full of ammo and you have to shoot it all before you can use the can.
Even paying the shipping cost its way cheaper to buy them on ebay than getting them at the local store. I bought a pallet full of 50BMG boxes from a guy about 200 miles form me. Including picking them up it only cost me me about $4.00 each.