Beyerdynamic A1 Headphone Amplifier 713708 Auction starts at $600. No reserve. MSRP: $891 (I'll use my outstanding reputation on eBay to prove that I'm reliable and honest. Unfortunately, due to eBay policy, we'll have to transact there. But of course I can leave positive feedback for you on Audioholics). I am a "Bronze-level Powerseller." I am also a "Top-Rated Seller" because I have always received positive feedback and have earned outstanding DSRs (detailed seller ratings). Although I have 100% positive feedback and over 318 transactions, I am not a business. I'm just getting rid of odds and ends around the house.