The method I used actually (currently) doesn’t require a physical Kindle. I just had to download a specific version of Kindle for PC (Version 2.3.70682) and was able to quickly and easily use the Calibre extension to remove the DRM.
I’m not super confident it’ll always work, so I’m not planning on buying more books from Amazon, but it’s a good solution to pull my existing library into the ePub world.
When my grandmother passed, my grandfather took most of her books to her favorite local buy/sell/trade bookstore and got a pile of store credit for my brother and I. It took us over a decade to spend it all, and we probably only had $300 or $400 in that account to start with. But the store sold most books for less than $5. Amazon is out here charging $25 for a 40 year-old book as an ebook, and there’s no equivalent to buy/sell/trade secondhand bookstores in the ebook space.