Well I think we need both Ken's (Kaysee88 and Schlotfeldt, owner of Badger) to clarify some things.
But, until they do, let's keep speculating, as it's kinda fun!
According to the Badger 2010 Price list still lists a Stock# 100-3 (GXF) UPC#0 4745910003 5 Desc. Gravity Fed Fine Head Airbrush Medium Cup (G Airbrush) List Price $122. This is their standard Fine head/needle, the one with only one line scribed on the blunt end of the airbrush.
They also show a Stock# 200-15 (M) UPC# 0 4745920015 5 Desc. Taxidermy Set (Medium Head) List Price $104. Which will have the needle with two lines scribed on the blunt end of the needle.
I've never heard of a Extra Fine head, and think that Badger's uneven nomenclature is throwing Keilau off.
I believe the only difference between the taxidermy set and the regular 200G is the taxidermy set is sold in a cardboard box.
So, Ken (Kaysee88) count the rings on the needle! It sounds like you have a 200G with Medium head, and you're good to go.
Though I still question the price. Where did you buy the airbrush?