Sorry I’m late with a response, folks! Been on vacation! 
A set of five diamond needle files advertised for $16.80; 8 piece
riffler file set (not diamond) for $6.95. Probably has diamond
riffler files, as well.
W.T. (or Wholesale Tool, not Western Tool as I previously stated),
where I’ve bought a lot inexpensive tools. They have seven
locations in the U.S.:
Warren MI: 800-521-3420; email WTMICH@AOL.COM
Indianapolis, IN: 800-551-2251; email WTIND@AOL.COM
Stoughton, MA: 800-343-1008; email WTMASS@AOL.COM
Charlotte, NC: 800-438-3580; email WTSOUTH@AOL.COM
Tulsa, OK: 800-331-4075; email: WTOKLA@AOL.COM
Tampa. FL: 800-237-4689; email: WTFLA@AOL.COM
Houston; TX: 800-231-4585; email: WTTEXAS@AOL.COM
If anyone wants more specific info (i.e., address, local phone
number) email me and I’ll provide.
Have fun,
Dave
Dave Sebaste
Sebaste Studio
Charlotte, NC (USA)
dave@sebaste.com
http://www.sebaste.com