has anyone used or using NS vendor portal?

I have some limited experience with it. What's your question? The out of the box version is very bare bones. I think each vendor can basically only see their own transactions/POs.

i kinda wanted to know the cost or would that vary? and what exactly the portal allows vendors to do...we're rolling out the PO process and was wondering if the vendor portal could assist in anyway

Vendor Login is free, just like the Customer Centre