Hmmm...
In the supermarket, sweet potatoes can sell for a range of
prices... I think from about $0.20 to less than a dollar, per
100g.
Sweet Potato Place sells their sweet potatoes $2.50/100g.
I think it's a bit pricey, but if we think about being able to
save the hassle of starting your own charcoal fire so that you can
eat just ONE sweet potato... heh heh, why not? 
Provided it's really sweet.
