These are great ideas -- you could also use them in initial salary negotiations and when something may be changing about your job (perhaps your boss wants you to relocate and you can get some extra perks to make the transition go more smoothly).

I am typically in the "more money is better" camp but I like Nora's mention that you may need to consider ramifications. For instance, I once advocated for an employee to get full-time status; what I (and she) didn't realize was that she was living in government-subsidized housing (across from the area community college) and her rent bill went from something like $25 to $400 (I don't remember the exact number but do remember thinking, did you not know that $25 wasn't a standard market rate -- these were fairly nice apartments). She was from a rural area and didn't really have any comparisons; to boot, she had been sending money to her parents, which abruptly ended. So, her status improved but her cash flow suffered.