Sonic Electronix via eBay offers the Sennheiser Over-Ear Headphones, model no. HD449, for $20 with free shipping. That's $28 under our mention from last month and the lowest total price we've seen. (It's also a current price low by $30.) These headphones feature a frequency response of 16Hz to 24kHz, duofol diaphragms, and tangle-free cord with gold-plated jack. Deal ends September 18.