It's legal. An annotated version, with neither the swastika nor a picture of the greasy Nazi fuck, was published a few years back and tens of thousands were sold, primarily to German libraries and schools. It's a good study on how shitheads think.
The copyright was held by the state of Bavaria as the official heir of Hitler and they simply said "Nope, no new printings."
As the copyright ran out in 2015 everyone can copy and print it again. Though most don't care, even the most right wing nutcracks realize that the book is rather badly written.
One more thing: While "Mein Kampf" is only available at rather high prices the books of Vladimir Putin are available for FREE on Amazon as EBooks and the printed version is €1. He wrote even years ago straight forward that he is willing to start the third world war to make Russia Great again and even laid out the list of nations he wants to subjugate: Ukraine was the first step, but in his ideology he also claims Alaska, Croatia, Serbia, Bosnia, Poland, Romania, Bulgaria, Finland and many many more nations. Overall he mentioned he would spare Germany, France and Italy but only because they have nukes and the US as their ally.
I often buy books written by shitheads when I end up studying fascism or other radical right wing movements. Heck, even more mainstream conservative movements with radical imagery or frequent dogwhistles. Reading books by shitty people on shitty topics is very important on understanding how the movements work and think.
Reading about fascism from antifascists is good and all, but understanding fascist movements when they are most active requires reading fascist works. Heck, even with books like Mien Kampf, a book with a ton of analysis done by antifascists could still be a potentially useful read for antifascists.
That's smart. I can't count how many times I've learned about new dogwhistles or the details of various ideologies and realized an acquaintance was a fascist and/or racist sack of shit, although I've never been surprised. This would help me realize in real-time, so I can call them out on their shit.
I do feel like I'd need a book cover with something like "I'm reading -book title- to understand scumbags. I do not support its ideology".
iirc it wasn't exactly banned in germany. Iirc the state of bavaria held the copyright and sued everyone who sold the book without their consent, while not printing any copies themselves.