From what I've seen, most of the people who have $50,000 trained PPDs never use them. They are just there for the trophy.
People who really need protection, either hire a bodyguard, buy a gun and learn how to use it, manage their lifestyle to avoid dangerous scenarios or all of the above. If you have $50 K to throw at a dog that you will probably never use, well... go for it. Doesn't bother me.
Which begs the question- why are PPDs so much pricier than a working police K9? A K9 is very likely to be used, and quite frequently, in his working career. He might very well fight a bad guy. A PPD is almost never used, I can't remember hearing a story of a celebrity and their PPD getting in a fight with an attacker, with the PPD staying in the fight and taking down the attacker. I have, on the other hand, frequently heard of police K9s tracking down a suspect and also staying in the fight with an armed suspect even when injured... perhaps it is simply opportunity and tells us nothing about the quality of the dog, but it does make me wonder.
This is my observation, too. Personal protection dogs are, in general, a lot of money spent for nothing.
My observation from owning several GSDs is that training them to protect me was not the problem. The problem was usually more along the lines of getting them to calm down and not eat the friendly visitors. I can't imagine how scary they would be if I trained them to be scary. As far as attacking people, they would go into "kill" mode if they sensed any danger, without me telling them to. No need for commands, because if it is that big a threat I might not be focusing on the dog, anyway.
Furthermore, if you launch a dog against someone who has not already attacked you, you could be up for assault with a deadly weapon, or worse. Then you get to court and the jury finds out you trained the dog to attack someone who had not already made contact with you, and you are done, both criminally and civilly.
I would much rather be telling a story to the cops along the lines of the guy hit me, or knocked me down, and my dog killed him on its own while I was helpless. And every GSD I have had would kill someone who attacked me - without training.