I’ve spent way too much time comparing e-readers. The cheapest option with audio right now is the 'Kindle Paperwhite (10th Gen)'—it’s not officially an audiobook powerhouse, but with Bluetooth support, you can pair it with Audible and get decent audio performance. The screen is crisp, battery life lasts weeks, and it’s waterproof for bath-time reading.
If you want something even cheaper, the 'Kobo Clara HD' occasionally goes on sale and supports audiobooks via OverDrive, though it lacks Bluetooth. It’s a solid choice for library lovers. For a more all-in-one experience, the 'Nook GlowLight Plus' is another contender, but its audiobook selection is limited compared to Kindle’s Audible integration. Honestly, if audiobooks are a priority, the Kindle Paperwhite is the sweet spot—affordable, durable, and versatile.