Sure thing, will give it a shot:
Garage Door Opener Motor & Gearcase: $9.95
http://www.surpluscenter.com/item.asp?item=5-1677&catname=electric
L050 Lovejoy Coupling, made up of:
Drive side, 1/2" Bore: $3.26
http://www.amazon.com/dp/B003HIWO0G/?tag=skimlinks_replacement-20
Driven Side, 3/8" Bore: $3.26
http://www.amazon.com/dp/B003HIWNX4/?tag=skimlinks_replacement-20
Rubber Spider: $2.10
http://www.amazon.com/dp/B003HIWQJK/?tag=skimlinks_replacement-20
10A DPDT Toggle Switch (Used for FWD/REV): $4.49
http://www.radioshack.com/product/index.jsp?productId=2062514
Single Pole 15A Light Switch $0.69
http://www.homedepot.com/p/Leviton-...t-Almond-R56-01451-02T/100669880#.UhGUWtKt3Ws
White Lithium Grease (I added this to the worm gear after the first batch to help it out with the load/duration, I had noticed some wear during the first batch but it's looked clean since I put this stuff on there). $4.58
http://www.homedepot.com/p/Lucas-Oil-8-oz-White-Lithium-Grease-10533/202535870#.UhGV7dKt3Ws
Other than the wood, the mill itself, and the stereo cabinet (which I bought at goodwill for nothing), I think that's it. Motorized for <$40!
Let me know if I missed anything and/or you still have questions about the guts. Happy to help a fellow cheapskate