You can now buy MTN MEGA bundle in BULK , which will be stored in your business section page, then you can start reselling each 1gb or more at your own rate.
And if you think our mtn cg or Airtel cg resell price much, then why don't you sell only 5 and 10gb of these networks, which is more cheaper than what Banks or other Fintech platform sells
Or better still, sell only GLO and 9 MOBILE, these two networks have over 80 million users in Nigeria, think about the big market share???