It seems that the HC series CMOS part 74HC(T)00 from the late 1980s is now the cheapest single-quantity equivalent coming in at about 30 cents. A quad 2-input NAND gate is hardly the most exciting ...

Using an old chessboard, eyelets, rings, weights, and string, [Alex] has designed a system that can show off all of the logic gates. This includes: NOT, BUFFER, NAND, AND, OR, NOR, XOR ...