I was in the same position a few months ago, and there was no printed version. My solution: pay for the damn book, use the required Adobe product to be able to unlock it, use a tool to create a DRM-free pdf (IIRC it was Calibre), and finally unistalling the Adobe product. I wish I didn't have to give money to DRM sellers, but in this particular choice I had no option.

Apparently this makes me a pirate, despite having paid for the product and not having any intention of releasing it.