I find you can make decent profits flipping the S9s with hobby, or entry level miners. I buy them when nobody wants them, and resell them locally when we get a decent price run up/FOMO.

If BTC runs up to ATH again they could be worth decent penny. Especially when new miners sell out everywhere. I've done this on the last 3 price surges. They are a easy sell because of the 120V, 1200W rating. Standard 15A circuit.