Bought a paperback years ago, it got wet & couldn't be salvaged. Found the same title on Kindle Unlimited, then decided to buy it. Word of warning: return the Kindle Unlimited version BEFORE purchasing. I didn't then found the transaction had been reversed, I'd been issued with a refund.
Now the Amazon website wasn't letting me download it to the Kindle. So I downloaded it to Kindle for Mac, traced the download location & added the title via USB. I have it on the Kindle now.