Groupon offers the Monster Earth, Wind & Fire Gratitude In-Ear Headphones for $54.99 with free shipping. That's tied with last week's mention and the lowest total price we could find by $4, although we saw them for $5 less two weeks ago. Developed with the band Earth, Wind & Fire, these headphones feature an in-line microphone and volume controls, right angle connector, two carrying pouches, and multiple eartip sizes. Deal ends September 25 at 12:59 am ET.