About SharePoint 2013 license cost.

Hi,

My organisation currently use SharePoint 2007 for limited purpose.

Contents have been stored to SP 2007 team site via desktop application(no users excluding administrator access SP directly).

and search has been used by non sharepoint site and desktop application using custom .net web services(this web service use search query object model for search)

Enterprise edition of SharePoint 2007 is there and its a single server installation with SQL is also on the same machine.

Now if we need to upgrade from SharePoint 2007 to SharePoint 2013, what kind of license will be needed?

Just one enterprise server license cost(as its a single serversetup)? or standard CAL licenses will also be needed?

Any information/help will be appreciated

Kind Regards,