negotiating with Microsoft?

I’m about to lead a team that’s re-negotiating some Microsoft contracts – Select and EA, along with some Open that cam with an acquired company.

Where can I find tips on what to ask for and what kind of special deals / concessions aer available when dealing with MS?

I’ve found plenty of info about license / asset management, and how to deal with audits, but nothing on this topic… Articles / links / consultants?

Thanks
Scott