Amazon offers its Prime members the AmazonBasics 3.5mm Portable Speaker, model no. ABPDP003, for $5.92 with free shipping. (Non-members can spend $25 or more to receive free shipping; otherwise it adds $5.74.) That's $3 under our June mention and an all-time price low for this speaker. It's also $7 under the lowest total price we could find for a comparable model elsewhere. It operates via USB or four AA batteries (not included).