Yesterday I was able to order 250 rounds of the FEDERAL TACTICAL 00 buckshot (the LAW ENFORCEMENT LE 132 low recoil rounds) from ammoman.com...i was going to post that it was back in stock, but now its sold out again...here's the webpage to keep track of it for anyone interested...
www.ammoman.com/webstore_12GA.htm

Tactical Defense Solutions has it for $4.25/5-rd box...its just a bit cheaper than ammoman IF you're looking for 100-rounds or less...