As far as I could tell the 2009 was not for circulation but could be bought in a presentation pack, like you said, for 1.99. A BU coin is just one that is brilliantly uncirculated, it doesn't refer to whether or not it was circulating.
That's why there were so few as opposed to the 2011 issue which was designed for circulation.
I do agree that the 2009 issue didn't draw much attention however the 29 design series actually got a lot of people into coin collecting. I've read that they have been one of the most held onto coins, with a lot more than half being taken out of circulation by the public.