From what I've seen thru Amazon's used books section, even at ~$50 you still got a deal on your copy. $26 is an absolute steal - I've seen them running well over $100. I still don't understand why Taunton won't do a second run on them - the demand is probably a thousand-fold or more from when they were first printed 30-odd years ago, due in no small part to the Internet and forums like this.
And you can download a pdf.
As to the morality of it all, the publisher has set on the rights for decades, won't republish, won't sell the rights back to the author
who never made a dime out of his hard work.
So if you're feeling "moral" about the whole thing, find an address for Will, and send him a $20.