I'm not sure whether this is an error or a last-minute clearance, but I'm not questioning it: Aerogarden's high-end Bounty model, which usually retails for $220 or more, has just been marked down 63 percent, to $84. It's currently still $230 on Aerogarden's site. Even though I already have one, this is still such a good deal that I'm buying another as a gift.When someone brand new to hydroponic gardening asks me which system they should start with, I almost always tell them to begin with an Aerogarden. These gardens have been around forever, and they’re famously foolproof and easy...