Amazon has the Adesso 2.4 GHz RF Wireless Mini Trackball Keyboard (WKB-3100UB) for $48 - 75% off coupon (Clip Coupon) = $12 with free shipping. Temporarily out of stock but still you can order it at discounted price.
Amazon has the Gigabyte GK-XK700 Backlit RGB Mechanical Gaming Keyboard for $40 with free shipping. Features Superior gaming mechanical key-switch, adjustable rubber feet stands, on-the-fly multimedia and backlight control.
Has good Amazon Reviews.