Aside from rare reports of amazingly low prices on Spark batteries, it looks like the price for a new one is still around $50.00. I'm seeing some of the more reputable outlets (B&H, Drone Nerds, etc.) offering used batteries for as low as $35.00 + shipping. They usually say they've been tested or refurbished and some sites even say how many cycles the battery has experienced. Even though I bought my Spark Fly More Combo off ebay from a highly rated seller and have been very happy with it, I'm more reluctant by a battery due to so many counterfeits. What are your thoughts on buying used Spark batteries?