I wish to integrate (Nigerian )online payment system into my website. But the cost of doing that is too much too and it does not favor new business ventures operator. Interswitch charges #150,000 one-time activation fee for you to be  able to integrate online payment system.

Is there any other company that provides online payment system in Nigeria?

In integrating Nigeria online payment system there are so many of them among which are Etranzact, Voguepay, eyowo, Gtpay, Zenithpay.

Apart from banks own other ones are free Nigeria processing system.
Apart from Interswitch charges Interswitch doesn't have a good support system if you send email for example it might take 2 months for them to get back to you only if they would reply at all.

I hope my reply about Nigeria payments system is helpful?
In my observation it seems that www.Voguepay.com has favorable reviews among Nigeria webmasters.