Wow, that's just down the road from me (I live in the 1960/249 area).
I called and spoke with them, they have plenty of 55 gal but no 30 gal. The gentleman stated that he gets calls all the time for 30's. Additionally, he stated, he never really runs across any.
So I'll continue looking however, going forward, if I need another barrel (metal or plastic), I know they are just down the street.