Lots of good perspectives here.
Before ever taking on an act of revenge, you have to first assess the situation and yourself. Its very important to first look at yourself, not to blame, but to make damn sure that nothing you have said or done, whether one time or perpetually, may have pushed this person away or initiated a response that ended up being them cheating on you or cheating you. If you can't find a reason why you may have been the source for their actions, then proceed ahead. If you can find something, best to just leave it be and walk away.
I'm a big fan and practitioner of delivering the oh so sweet justice of revenge to those who truly do deserve it.
They will always say they are sorry, but they are really just showing a form of self pity that they were caught, and are likely not sorry at all. Some may actually regret their actions too, but, you have an obligation to discount this for the next rule below.
However, its the fact that YOU were not given a choice. That's the one part that most cheaters and scammers will always disregard or never even consider, and that sir, is where the "pain of being cheated on or led on" derives from.
Remember, THEY took action, for whatever reason, and deemed it justified enough for that moment in time.
Therefore, recourse is and can be justified. How you measure that, is up to you. Don't go too far. If the person offers to compensate you, through whatever means you see fit, accept it only after you adjust it according to your needs. Also, don't wallow around in mental masturbation, because it is not healthy. You need to vent it aka follow through.
By all means, go and fuck around with 500 other women to dull your pain. But NOTHING feels as good as the orgasmic sensation that proper revenge delivers.