The worth of any product is that which the market dictates. Check the situations vacant, that should give you an idea.
There is no point in thinking I do this this this this and this, so I should get that, unless you work for a small company where you can turn the screw to get paid your worth.
Most business people think like this. Whats the worse thing that can happen, what is the likelihood of that happening, and what would I do to deal with it if it did happen.
Keep that in mind when negotiating, as if you threaten to leave, you can bet your pay cheque that your boss will have considered that as an option (if he is any good anyhow). Many years ago, out of the blue, my boss, the owner of the company called me into his office, and told me he was moving my salary from £9,100 to £17,940 and also giving me a company car. I was gobsmacked at this, as I had been feeling exploited for a while. I left that post in 1984, and about 18 months ago I was at a presentation and this guy was there. I had to ask him why, it had been bugging me for years.
He told me that it was not personal, he could see that I was not happy, he simply sat down and worked out what it would cost to replace me, in salary and additional costs, so he decided that if he was going to spend it on someone, he would spend it on me. He then told me that he knew I placed loyalty high on my list, so he knew that I would not consider leaving him for at least another 2 years after that. He played me like a piano, and there was me thinking I was special
If you are looking for a rise then you should sit down and present every worse case scenario to your boss, steal his thunder by telling him the score. Then tell him what you want. Also ask yourself what it would mean to YOU if he called your bluff.
There is another option, if you ARE as good as you feel, you can offer to work as a consultant