The BBC reports that a bike, worth about $50, is seen as more desireable to militia members than their gun:

A scheme under which gunmen in the Democratic Republic of Congo are given bicycles in exchange for their weapons is being extended due to its success.

Ngoy Mulunda, a pastor in the south-eastern Katanga region, says he has been given some 6,500 weapons in the past year, which he has destroyed.

That’s a lot of bicycles. Apparently metal roofing and goats are also offered for trade in other regions.