Whenever an organization prices its products, it should price them based on their cost to produce and market and the value that the product brings to the customer. Candidates are marketing themselves so they should do the same. They should price their services based on the cost and on the value. For the cost, I would look to the salary calculators as it gives you a good feeling for what others are charging with similar credentials. But for value you need to get more creative. You need to estimate the additional revenues that you'll generate for your employer or the expenses that you'll save them. If you find that you'll save them $250,000 per year and they're offering to pay you $25,000, you should realize that they have some flexibility especially if you provide those numbers to them as the hiring manager is probably in the dark about your value just as much as you were before you pulled out your calculator.

Many candidates object by saying that it is too hard to estimate their value. Wrong. They just need to get creative. Let's look at an administrative assistant. If he figures out a more efficient filing system that takes one minute to find each file rather than two minutes under the old system, then that's a real cost saving. Now extrapolate. If 25 files are pulled per workday, that's 125 files per week and 6,500 per year. If the person pulling the files makes $20 per hour plus benefits and payroll taxes, that person probably costs the employer about $30 per hour. The new system saves that person 6,500 minutes per year or 108.33 hours. At $30 per hour, that's $3,250. Now do the same for everything else that you can do for the employer that generates additional revenue, saves them money or both.