I know of companies that have shaved off 75% their On-Premise SQL Server costs
 
Microsoft Cuts SQL Azure Storage Pricing http://redmondmag.com/articles/2012/02/14/sql-azure-storage-pricing.aspx
Pricing Overview https://www.windowsazure.com/en-us/pricing/details/#database/?WT.mc_id=cmp_pst001_blg_post0055pri

One of the members (Robin is an MVP) of my community absolutely loves SQL Azure. She will flat out tell anyone that her company saved up to 80% of their costs for maintaining their own database infrastructures. If you don’t believe me, I can put you in contact with her.
  These prices are dramatically lower
 
Database Size Price Per Database Per Month
0 to 100 MB Flat $4.995
Greater than 100 MB to 1 GB Flat $9.99
Greater than 1 GB to 10 GB $9.99 for first GB, $3.996 for each additional GB
Greater than 10 GB to 50 GB $45.954 for first 10 GB, $1.998 for each additional GB
Great than 50 GB to 150 GB $125.874 for first 50 GB, $0.999 for each additional GB