eBay has the Logitech Prodigy G403 Gaming Mouse & G213 Gaming Keyboard Combo for $65 with free shipping. Retail price: $140. Has excellent Amazon Reviews.
Amazon has the UtechSmart Venus Precision Laser MMO Gaming Mouse (US-D16400-GM) for $39 - $11 off with coupon ELEIS6GB (Ends 3/31) = $28 with free shipping. Features a 164000 DPI sensor, customizable lighting, 18 programmable buttons, on-the-fly DPI adjustment.
Has good Amazon Reviews.