Static IP

Hi,

I currnetly have a dynamic ip assigned to me by my isp. I have a router and 2 boxes attached..

I would like to eventually host a small website and looked into getting a static ip..

If I get one static ip and give that address to the router do I need to buy more from my isp or can I just set up the router to hand out ip’s using the same sub net?

Becuase If i have to buy more they want me to buy there router yeah right…