Hi Saurabh,
we do not use SCN for license discussions, because it should be a technical forum. You can get an idea about the SAP pricing here: https://store.sap.com.
But you have to contact in case of SAP NetWeaver Single Sign-On your SAP account executive about the final price. In case you buy your SAP software via a reselling partner, you should ask the partner.
read somewhere that this is now not supported by SAP and we have to only use NW SSO
SAP recommends to use SAP NW SSO for SSO but you do not have to use it.
Regards
Matthias