I think the only remaining Kindle model still in production that offers audio capability is the Kindle DX. But the DX is very old technology now and is $199. I doubt they are still actually building them, most likely just selling off existing stock to get rid of them. If you can find a used
Kindle Touch or a
Kindle Keyboard, they both had audio capability. But they are no longer in production.
ETA: If you click on the list of retailers links in the linked pages above, the Touch is selling used from about $43 and the Keyboard is selling used from about $93.