The premium you pay is for an extra 3 minutes of flight time. People are apparently failing to remember that the battery 'in question' is a STANDARD P4 battery that was replaced when the
P4P came out. Your suggestion that he buy one of these older P4 batteries from an 'authorized' dealer is advice that he likely cannot follow. They are old stock. That is why they are so much cheaper.
So, IMHO, you could have paid 105.00 and gotten a battery that has about 90% of the capacity of the 169.00 battery. They are both DJI batteries. Nobody has offered ANY evidence, other than conjecture based upon fear of the Chinese language and LED's that glow too bright or not bright enough, that the guy selling the 105.00 batteries on eBay was selling anything OTHER than official DJI gear.
I am not saying this just because I bought one and it has worked flawlessly. I am saying it because it is MORALLY WRONG to accuse someone of dishonesty when there is no evidence to really back it up. That is why I keep chiming in.
They guy got his hands on a pile of old stock P4 batteries. He sold them for a good price. Nobody has yet to show that the battery is not genuine or that one has caused problems. Nobody has yet to bring up a single issue relating to performance. All of the suspicions are focused on a misspelled word (mine has that too) and LED's that are not exactly like the ones on another unit.
If you buy an Intel Processor that is made in the USA and the documentation is full of things like "Intel are make chips with hands of hawk swiftness" then you got a problem. Someone for whom we KNOW English is a second language, at best, misspells one word? I say they probably did a hell of a lot better than a U.S. Company would do with a set of Chinese instructions.