Patuoxun via Amazon offers Prime members the Mpow Bluetooth 4.0 Audio Adapter for $30.99. Coupon code "WT38MPOW" cuts it to $23.99. Prime members bag free shipping. (Non-members can spend $35 or more to qualify for free shipping; otherwise, it adds $5.14.) That's the lowest total price we could find for a wall-powered Bluetooth 4.0 receiver with a 3.5mm output by $26. This adapter can be paired with a Bluetooth device and provides audio data to a receiver via 3.5mm jack.