Like snginc said, it's not going to work anymore. That ship has sailed. Back when PLR was just becoming popular, people made a killing doing this. But Amazon got wise and it's not possible anymore.
And again, like snginc, you have to rewrite the ebook so much that it would take a LOT of time. I mean everything needs to be rewritten, even the contents page. Rewritten and reformatted and then of course you have to have a totally unique cover (which is the easiest and quickest part of the whole thing). Basically what you'd be doing is using the PLR item for ideas, then write a your own ebook based on those ideas. And in that case, you can use any book, not just PLR books, because you're not copying the book, you are just taking the ideas and writing them in your own words, expanding on them, etc, etc, etc. You are basically just writing your own book, which isn't what most people who buy PLR are willing to do, lol.
But ultimately, from what I have read about selling kindle, it's not worth it unless you sell certain genres and you have to really know how to work the Kindle system. Most of your books will be selling for nothing and at most $1.99. There are ebooks and courses on how to make money with Kindle, but to me, it sounds like all you are doing is writing books to fill Amazon's catalog with cheaply priced books and hoping to make money. The only way this could work, in my eyes, is to find a small army of offshore writers who can produce decent quality books, fast, without copying other people's work...and do it all for cheap. Good luck with that. It will take a lot of time and money to get to that point.