This is a follow-up question to this question of mine, where I wanted to know if academic salaries can be negotiated.
How does an academic negotiate a pay package that has been offered? What special points in one's profile must be emphasised in order to get a favourable bargain? Are there any standard cards (tricks) that must be played?
PS: The negotiator is assumed to be fresh out of his doctorate.
I think the first thing you need to ask is do you want a raise. While it may seem obvious that more money is better, I would argue that this is not the case since the raise comes with other "costs". In the simplest case, would you rather a raise of x, or an increased startup package of 10x? While not directly linked, your total "cost" (including space) is a factor.
There are two problems with seeking a raise. First, they are hard to justify. Universities want you to do good research. The effect of a raise on research output is hard to see, while the effect of an extra RA for a year is easy to see. Further, a small increase in salary now projects to large future costs for the university. The university will keep that number in their head during negotiation. A raise means you might top out on the pay scale earlier, so your pay may stagnate (meaning the university over estimated the cost of the initial raise). This means that overall the raise is not good value for money.
You might argue that a raise is the only way increase the money in your pocket. In the short run this is true, but in the long run, better research might lead to more money.