I'm also a member over on the IAP (international association of Penturners) forums, and they recently had a group buy on a pen mill set. for $38 including shipping I picked up two of these:
that's a set of shafts with interchangeable heads, in 7, 9, 10 and 11 mm.
the set came with a 4 blade head, I ordered an extra 6 blade head to go with each one.
wow, macro photography at its finest...