This is business 101. Price is exclusive of cost. Price is determined by what the market will bear.
RK’s link to salary survey, and any other salary survey you can find is the only thing that is relevant. That is “price”. That is determined by the market. Your “cost” is irrelevant. Your employer doesn’t give a crap, nor should they.
So when you negotiate, leave your cost calculator at home, it is not a legitimate negotiation tool.
The following numbers are used for illustrative purposes only:
Them - We would like to offer you $50K.
You - According to this survey, a person with my experience is earning $60K in this area. Can you start me at $60K?
Them - No. We have to start you at $50K.
You - I understand a new hire is a risk. And if my reviews go well, how quickly do think I can ramp up to the typical pay in the area?
Them - I can’t say.
One of possibly countless scenarios, but either they are willing to negotiate, or they are not. Again, my advice is to think about your response before you make it.