Business Justification for SharePoint 2013 : Why can’t we do this in 2010 and spend the money on the staff party instead!

Hi community

I have spent today looking at the various licensing options for SharePoint 2013, such as Select Plus Volume ( with the minuscule Public sector discount ), EA with the discounted SharePoint Server licenses + nn ( std + ent) CALs , perpetual and subscription license models . Then there is SharePoint online P1 and P2 and  oh yes, everyone’s favourite Office 365  E 1 -3 plans ,  then you need to add the VS2013 MSDN subscriptions with SA…… Then there is the Yammer debate: free on Ent to factor in ……

Against this backdrop, I do need to put some strong business reaons as to why my client would want to make the upgrade on (on prem or cloud) SharePoint 2013. I could do with a bit of help here as I will need to counter such arguments as :

• SharePoint 2010 does have some mobile support and  you can even add responsive design changes to the master page and CSS . On top of this there a products such as SharePoint2Go that provide the HTML 5 rendering on certain types of lists and page in SP1010 How much of a cost saving ( reduced development etc) is SP2013 going to make ?
• You get discussion boards, team sites, blog sites etc in SharePoint 2010 so how is SharePoint 2013 going improve the collaboration with the organisation
• With regards WCM . How much of a big deal is the new Cross Site publishing going to be if say we only have one site collection- though having the choice between CQWP and CSWP will be nice,even on a single etc
• Search in 2010 can be configured to say find the phone numbers in user profiles and have this surfaced on the home page so why do I need the search in SP2013.

These questions and more will quite rightly be voiced which I need to have some good case studies or strong evidence to backup my recommendations to go SharePoint 2013 ….