Kmart offers the Nakamichi Mini Speaker in Black, Green, Red, Purple, Yellow, or Silver for $14.99. Plus, Shop Your Way Rewards members will receive a $10.15 SYWR credit. (Not a member? It's free to join.) Opt for in-store pickup to dodge the $5.99 shipping fee. Assuming you'll use the credit, that's $15 off list and the lowest total price we could find. It features a a microUSB port, 3.5mm earphone jack, frequency response of 150Hz to 18kHz, and a playback time of three to five hours at 60% volume.
Of note, Shop Your Way Rewards members may be eligible for additional credits and discounts.