hey steve,
i actually have the extruder screws in stock, but for some reason i havent put them up on the store yet. i'll correct this oversight.
i'm still waiting on a shipment of the bearings, but i'll put those up too when i get them.
Forrest is right: its actually not too hard to make the drive screw with a drill + a dremel. the machined ones are definitely very nice though. i'll have more info soon.