WowitisCool offers the Kilayvoice Mini PA Speaker System with Microphone Headset for $24.96 with free shipping. That's the lowest price we could find by $5 for a similar model. It features a uni-directional microphone, up to 10 hours of use per charge, and an 11-watt output.

Need more? Buy two or more to drop the price to $21.96 each.