Combo bundles, from a keyboard-and-mouse set to a tee.
I bought the Logitech MK260 Wireless Combo, keyboard and mouse, from Challenger for S$39, or S$36.90 with member's price. It's one of the cheapest branded wireless combos I could find there, the main alternative being the Wireless Desktop 800.
Street Fighter players will recognise Akuma's Raging Demon move. Thanks to Benjamin's tip, I bought this Akuma's Heavenly Combo T-Shirt from GameScore for S$25. GameScore likely earns just a few dollars, since SplitReason sells the same shirt for US$19.95.