got a note 9 for this price albeit not new but note 9 in excellent condition
I use it heavily (mainly professionally, but for casua use too), and also know many others who use it. It's a gimmick for some, but for those who use it, it's an extremely handy tool. But you got to know how to use it, otherwise, it's pointless.
Yes, looks like a bot dropping the price until it gets some bites? They probably do this all the time, as I have seen patterns like this before.
Price has shot back up. If as you summise it's all priced by algorithms, I guess a sudden rush of sales (due to the low price) has put the price back up?
I suppose it's slower which might be less of a strain on the battery. Could just use a lower power wired charger in that case (1A or similar)