alt Hacker NewsI can't vouch for it personally since I don't own one, but I saw a video on YouTube mentioning the Innioasis Y1[0], which supposedly does a decent job of replicating the iPod experience with some modern features like USB-C and Bluetooth at a decent price. Can be flashed with RockBox. No external SD slot, but it can be opened to swap out the SD card it comes with. Reportedly doesn't feel nearly as nice in hand as a real iPod does but that's pretty standard at this price point.
Damn this looks great. I'd guess the main difference in feel is the weight. iPod classic was about 2-3x heavier, which seems to be the main factor in premium feel.
(Well, that and the metal body.)