Motors and Controllers Price Range..

What sort of control are you actually looking for? Precise speed or positioning? If so, that may be fairly sophisticated, and thus expensive.

You should search Ebay. I've purchased many used and new variable speed AC drives (1-3 phase in, 3 phase out) and DC motor drives up to 3HP ratings. All of them were well under $100 and all of them were 100% functional.

Just saw (4) 1/4HP AC drives sell for ~$80 (140563101207). That's $20 for each drive.

Specs were:

Input ,1-ph, 120V, 6A

Output, 3-ph, 0-240V, 0.25 HP, 1.6A, 0-400 Hz

You would need something a little larger for a 3/4 HP mill (I suggest 1 HP). If you use the right search criteria and wait patiently, you could get one for ~$50. IF you are willing to pay ~$100, you should be able to get one almost immediately. Best wishes.

monsterscooterparts.com has some good motors in their recreational scooter section. probotix.com and kelinginc.net seem to have good controllers which can be used for automation, I think.

Try using automobile motors like: Wiper motor or power steering motor; these must be cheap due to huge volume manufacturing.

Here's a source for time delay relays, and power supplies. factorymation.com

PC power supplies are also good, (mass produced) but for the trouble of bunching the wires maybe not.

I used a corded drill and a C clamp to hold the trigger at the speed I wanted it. Motor, power supply, speed controler ~$60

DIY. You can find easy schematic for low W controllers on the internet.

http://www.google.is/search?q=schematic%20for%20low%20W%20controllers&um=1&ie=UTF-8&tbm=isch&source=og&sa=N&hl=is&tab=wi&biw=1280&bih=899