It seems there can't be too many warnings like this. Africa, especially
Nigeria, is notorious for Internet scams.
Of course, even here in the good ole USA, don't let anyone have anything
until their check has cleared.
Licensed and bonded escrow services are available to hold money, titles
and even hard items until everything is straight up.
There really are dealers in other countries that specialize in importing
used merchandise for resale but only the "big boys" (professional
import-export businesses) should deal with them.
Al