Walmart offers the QFX 8" Portable Party Bluetooth Loudspeaker with Microphone and Remote for $27.10. Opt for in-store pickup to dodge the $5.99 shipping fee. That's the lowest price we could find by $16. Features include:

4,400 watts peak power

adjustable treble and bass

LED lights

USB port, microSD cart slot, & 3.5mm input

up to 4 hours of music per charge