SQL Server Licensing is depends on which edition your are buying and under which licensing scheme your are buying.
Microsoft do have special rate for special customers, but actual pricing you need to contact your Account Manager / Sales representative only.
But in general, here is the standard rate card for SQL Server 2012 Licensing.
SQL Server 2012 Standard Edition Cost
starting at $2,000/processor license.
SQL Server 2012 BI Server Edition Cost
–$23,000 (50 user) license.
SQL Server 2012 Enterprise Edition Cost
–$54,000 /processor license (8 cores)
SQL Server 2012 Express
Note: – This is approx prices taken from Microsoft and these varies, please contact Microsoft Sales representative or account manager for actual pricing.