This thread is probably what you are looking for. There were some pretty good answers there.
Quoting my favorite comment, marked as spoiler just in case: [>Ever since I've read the entire book saga when I was eleven years old or so, I've been analyzing Geralt's morality and world outlook in a couple of ways, seeing as it was the Witcher series' that inspired me to take up writing myself.
Putting it very basically, Geralt of Rivia is a good man at heart, even if he doesn't want to admit it or show it.
Geralt, although he does his best to appear as a True Neutral, is actually a Good Neutral when you analyze his persona more in depth.
Take a look at the 52 and a half short film (maybe it was a story, too - I don't remember at the moment, I've read the books 10 years ago, lol), where he agrees to wipe out a cave full of monsters for chump change solely because they're a danger to the local populace.
Look at how he kills Renfri and her thugs in Blaviken, only because he was convinced she's going to use the villagers as bait. This act, although completely selfless and aimed to help the people of Blaviken, earns Geralt a reputation as a ruthless killer - the Butcher of Blaviken.
The reason he doesn't engage in politics is not because he doesn't care about the people on either side, but because he knows that if he picks a side, he'll have to hurt someone on one part or another, and that it'll in general bring more trouble later than it is worth.
How about the Rivian Pogrom, where Geralt was impaled on a pitchfork and killed? He didn't take part in it because the peasants attacked him, no. He stood up for the non-humans, the elves and dwarves, defending them from the angry mob. His killer, Rob or something, was a peasant that appeared to "yield" to Geralt, and Geralt accepted it, seeing that the man has ceased hostilities against the non-humans.
And then he gets stabbed in the back and murdered by the man he's just spared. In a way, Geralt of Rivia is a tragic, Neutral Good pseudo-antihero, rather than a legitimate True Neutral.
He simply makes himself appear as a cold blooded monster slayer because that's what society expects from him, that's what is going to get him employed and feed him.
Why does he haggle on fees? Witchers are horribly underpaid, compared to fully human monster hunters (look - Witcher 1, the Royal Huntsman gets paid a 100 oren or something like that per drowner killed, Geralt gets 400 for taking out a whole nest of them) and thus they NEED to be shrewd in order not to get scammed by their employers. He haggles when he knows his employer can afford the sum, not because he wants to bleed everybody dry. Just look at 52 and a Half.
That's one of the morals the book tries to teach people: do not judge a book by its cover. Witchers are known as killers, monsters, mutants and rabid beasts, yet when you actually look past all the stories and how they look, you'll find out that they may be some of the kindest people in a world full of evil.
... aaaand that's all, folks. I guess, lol. I get WAAAY to excited about anything Witcher related, and it's been like this since... 2003? Or something like that.](#spoiler)