The one that Nigerians started using recently is Avangate. Just have a look at the pricing. 2CO looks interesting. thanks! I will let my friends have a look.
That is absolutely ridiculous pricing! I guess there is one gateway anyone can use regardless of country is: http://www.mastercard.com/us/company/en/whatwedo/payment_pro...
Ofcourse it does not have a transparent pricing or subscription module, but you could overcome that by integrating with any third party app spreedly, chargebee etc
[1] http://www.avangate.com/pricing/