I don't know about cheap but I just bought 25 ft of (Black SOOW 600 VAC Service Cord 12/3 Awg, .60" OD) electrical cable from mcmastercar for about $44. This is to replace the 10ft cord on my cabinet saw which is too short.
~mark
+1 for the Rockler 12 gauge on sale. Easily converts to 240V if so desired as most flexible cable works up to 600V (printed on jacket). Obviously heat concerns still apply.
I've got 2 of the Harbor Freights that look just like the Griz. On sale $35. Regular about $60.
"A hen is only an egg's way of making another egg".
– Samuel Butler
Might search for surplus Appleton Reelites, first class cord reels at a price guaranteed to cause a coronary but sometimes can get lucky & get on at a good price.In otherwords, they are real expensive but worth looking for surplus, fleabay, auctions .....
http://www.appletonelec.com/