For COST: http://blogs.technet.com/b/keithmayer/archive/2013/09/09/vmware-or-microsoft-shopping-for-private-clouds.aspx

For Technical comparison: http://blogs.technet.com/b/keithmayer/archive/2013/09/24/vmware-or-microsoft-comparing-vsphere-5-5-and-windows-server-2012-r2-at-a-glance.aspx

For a company under Microsoft enterprise agreement :
operating system: windows 2012 R2 datacenter 2 physical sockets = 3593 euros        (Unlimited VM – no hidden cost)
system center datacenter 2012 R2 = 1902 euros for 2 physical sockets                      (full system center suite covered including SCVMM – no hidden cost)