Some ICANN approved registrars do offer discounts and specials (e.g., www.Dotster.com), just be sure to read the fine print (e.g., costs associated with making any changes in registration information), inspect their service (e.g., do they list a toll free telephone number, how quickly they respond to email), and consider their services.  Some sites do offer bulk discounts (e.g., www.Register.com).

Some Three Stooges sites:
http://www.byrum.org/3stooges/sites.htm
http://members.aol.com/mike6099/stooge.htm
http://wav-emporium.forsite.net/wav5.htm
http://www.galent.com/camelot/jukeboxa.htm