explain to me, "you get what you negotiate." ?

That phrase is meant to be contrasted against the familiar saying "You get what you deserve." In business, you can't expect people to be fair or to simply give you the best deal right from the start.

An example would be if you are hired for a job, and the other two people who do that job and have the same qualifications and experience as you are being paid $12 an hour, you might assume you "deserve" $12 an hour. But in fact you might be offered less. And you might need to negotiate in order to get more money.

So the point is that in business, you don't get what you deserve, you get what you NEGOTIATE.

It means that you get a better deal is you argue your case. Such as a higher salary, or a lower price.