From my experiences, here are the questions you should be able to answer expense-wise when entering into the interview stages - within your company for renegotiation or even at another company.
What is the current worth for your skills in the job market
What is the extra value - YOU - bring to a company, for which you can demand a premium on your market worth
What is the company you are interviewing with REALLY looking for?
What is your immediate manager REALLY looking for?
What is the sector you are entering and what is the future way to carve out the next steps from there?
What is the role you are targeting and where do you plan to go from there?
What are your expenses like and what is does your desired lifestyle entail expense wise?
What benefits is the company providing you - what financial value can you assign to the benefits?
Which networks are you breaking into? What is the future value of such networks?
How much effort is it to get acquainted with the new role?
How much does this company, I'm discussing with, need me?