Create new site for registered and not registered users

Hello, counting on your help.
I offer to the visitors to create there sites with my multisite/ buddypress.
I’m using Blog Templates plug-in.
In case if visitor is not yet registered and clicks on Create site button (http://myolia.com/register/) gets redirected to the register page where one can create an account, choose the template and so on. Everything goes as planed.

My issue is for the already registered user. If user who already has an account decides to create a new site I have to have a deferent pass (http://myolia.com/sites/create/). So I’m ending up with two buttons where one of the buttons is always a dead depends whether visitor is registered or not. My question is how can I have only one button serving both cases?
I did my best to describe the issue, but it still might sound confusing the site is on very early stage but please visit it for better understanding. Myolia.com
If you require the access to my dashboard- no problem.
Best regards,