If they are asking for input then I would not just be thinking about a
salary comparison. Pay rises have to be earned and you need to prove you
have earned it.
What have you brought to the business this year to make it worth investing
more money in you, you have skills but so do many others, and many will do
your job for less and may bring more. How are you going to convince your
boss your worth a pay rise? What about softer less quantitive values you
bring to bear to support the technical aspects you have, you may already be
ahead of the game frinancially so need to use other areas to justify a rise.
Why dont you write an appraisal of your year, what you have delivered - what
you have done well and ask your peers or curotmers to provide some feedback.
Also, go in armed with two things you will improve on if your request is
denied or even granted (the things obvious to you and to others) and agree
when a rise will happen if you improve on these within an agreed deadline.