I put down $5 grand plus, but every case is different. Remember, self defense is not a "right", it is an affirmative defense to a charge of murder or manslaughter. If the shooting is in the shooter's home, and there is no other involvement (e.g., a drug deal gone bad), the police will probably not make an arrest, and there will be no charges; a civil suit is still a possibility.
But, in a shooting outside the home, the shooter will almost always be arrested, so lost work, etc. can be a factor. If the prosecutor chooses not to press charges, that is the end of it from a criminal law point of view.
But if charges are pressed, and bail is required, a bail bondsman will charge ten percent, non-refundable, of the bond amount. Bond may not be allowed if the charge is murder, but even if allowed may run to, say, a half million. That means someone has to come up with $50,000, in cash or collateral that they won't get back.
Attorney's fees can run $500+ per hour, depending on the lawyer and the case. And on, and on.
Then, if the criminal charges are dropped or the outcome of a criminal trial is successful for the defendant, the shooting victim or his survivors may file a civil wrongful death/injury suit. Charges for defending that suit will pile up also.
In other words, the idea that you can just shoot someone, claim self-defense and walk away whistling is something that happens in movies, not in real life. The fact is that, web site ninja nonsense notwithstanding, shooting or killing someone, even in a clear cut case of self defense, is NOT taken lightly in modern society.
NOTE: Before responding with silly nonsense about how YOU can shoot half the county, claim self defense, and be awarded a medal by the governor, THINK! You will NOT be the exception, and if something does happen, the more you rant and bluster about gun rights, and how want to shoot people, the more likely you are to get a lot of prison time.