Another impossibly light unit from KCNC, this flat bar weighs in at a barely believable 119g. The Bone is constructed from T-7451 Scandium alloy, is 600mm wide and comes in standard and oversized clamp diameters.
KCNC are best known for their super-slinky drilled out bits but the SC Force handlebar is a simpler beast, a fairly standard road drop made from T-7451 Scandium alloy that's light and comfy, and not too pricy either.
Cinelli's Vai handlebar has been around for a while now but it's still well worth a look. As the ancient engineering cliche goes, pick any two from light, stiff or cheap. The Vai certainly ticks the cheap and stiff boxes, but light it ain't.