I love this 1950s advertisement for the "Motorola 6 Transistor Portable" radio set. Billed as a "big speaker" with "fine tone" and "long battery life (10 hours)", its virtually identical to ads today for bluetooth speakers. Interestingly this seems particularly marketed toward females: "fits your palm... or his pocket."

Not sure how much $24.95 is in equivalent cost today, but that sounds like an expensive gadget.

UPDATE: Apparently that is the equivalent of $257 in 2018 dollars! [Thanks, sanpura on Reddit.]

Honestly, I kind of want one. And amazingly the same style radio from that era can STILL be had for $24 on eBay! [Nice sleuthing, leggup on Reddit.]