Here's something I listened to recently, "The Coddling of the American Mind", as available for purchase across different platforms:
Audible (Amazon) is selling it for $12.60 (or 1 credit, $10.66/credit, or $14.95/month)
Apple is selling it for $14.99
Barnes & Noble is selling it for $20.00 (or 1 credit, $14.99/month)
Kobo is selling it for $20.99 (or 1 credit, $9.99/month)
So, if you're buying it outright, Audible is the cheapest, and Apple is a couple bucks more.
If you know you're going to be listening regularly -- and you should -- then one of the subscription plans makes sense.
I've had an Audible subscription for over a decade, so that's what I'd use -- but if I was starting over today, B&N is stiff competition, and Kobo -- which I hadn't even heard of, sorry -- is the cheapest.
Either way, the difference is less than a cup of coffee in most places, so picking which one shouldn't be an excuse to procrastinate on reading!