Hi. Does anyone know where I might get a reasonably priced Inogen One G2 backpack? The carry bag is fine but if I don't want to carry another bag it gets a bit full with a spare battery, wallet, phone, etc etc. The G2 has now been discontinued so I'm sure there must be a few out there. I've tried eBay, Gumtree, Exchange & Mart, etc, for a second hand one. I'm really not prepared to pay over £150 for what's basically a customised rucksack!