Dingiswayo also encouraged trade and opened relations with the Portuguese at Delagoa Bay, bartering ivory and oxen for brass and beads.
In Barth's time American merchants were established on the Niger, bartering goods in exchange for slaves.
Not much for bartering and competing for an item in an auction environment?
This type of bartering of knowledge is quite beneficial to homeschooled students, particularly high school aged students who often need more specialized topics.
Use a bartering system for your older child as a way to reward positive behaviors.