I am worthy of increasing my income.

Worth and price are different systems, and the second one gets negotiated in rooms, usually badly.

The commonest reason people are paid less than the person sitting beside them is not skill. It is that the person beside them said a figure out loud, waited through the silence, and did not fill it.

That silence is the whole skill. It lasts about three seconds and it feels like a fortnight.

You can rehearse it. Say your number to a wall until it stops sounding outrageous in your own mouth — which is not a trick, just the ordinary way anything unfamiliar becomes sayable.