A man is known by the company (of friends) he keeps.
It is a well-known proverb but one can translate it into another way skillfully.
Your profession, precisely speaking, your tasks and responsibilities tell how worthy you are in an industry or in a company.
Speaking about a technical occupation, it is necessary that a skilled employee not only possesses expertise to sell his mind and brilliant ideas, but also keep abreast of further tasks and next steps to show how responsible he is in his field.
Factorizing ones abilities at a certain position at the company brings a uniqueness of his/her level.
Simplifying it in other words, if you are working within a small team of 15-20 highly skilled engineers and scientists and your position is to lead and manage, then you are the one who is responsible for the outcome of that project handled to you or your team.
With such a scenario, you can easily figure out your worth and sell yourself.
Indeed, one has to be flexible within a range of his responsibilities and tasks for the job to what he is getting (salary).
Now let us extend the picture to a position of a product manager who bears a crown.
It is rightly said by Shakespeare

uneasy lies the head that wears a crown.

A crown is termed here as a bunch of characteristics and unique tasks which no other person in the company can handle.
The product manager is constantly under stress because he has beautiful skills and is given those tasks.
Therefore, it's his expectations too, to gain the suitable pay-scale for which he is carrying the crown.
Of course, it is he who is controlling the major production of the company.
A single false calculation or wrong step can error in million Euro.
Sometimes one's salary scale does not match with the position one keeps.
It may lead some uncomfortable situations, frustration or overload etc.
But then there is a way out to tackle that problem.
In most of the companies, there are human resource department that handles a 3rd party like conversations with you and your employee in order to settle the disagreed issues about average salary and the responsibilities which you are assigned to.
Actually, an open and an honest conversation among the party members leads to a very healthy results.
Hence one can flush away all the accumulated misunderstandings (if they are there too) and finally can achieve what his salary demand is (within an average or a range).
Since state-of-the-art technology demands a solid technical approach and plans, therefore it is also necessary to maintain ones managing, planning and leadership skills too.
It is far better to first figure out your own skills and abilities, then rate and compare it to other candidates for the position in a company and other markets as well.
You should Google out your market level and prepare well about yourself.
One can indeed think of the fact that if he is hiring or employing an expert person for his own company what could be necessary to consider and decide between his salary and his given tasks.
Of course, one can end the discussion saying, "I will work within a team, but can lead and bring a product in the market independently and for that I rise myself to that level of salary".
Consequently, to cross the average salary range market, one should keep best informed about the competences and accomplish the tasks well in time.
In this regards, a clear communication (both verbally and in writing) paves a wide road to success.
Planning achieves the infrastructure and your personal triumphs reveal your destination to you.