I have one but I sprang on the whole space-heater setup.

FYI, their optional vonnets wifi adapter was not compatible with my router (something to look out for), and even this small fuss had me pulling my hair out for two days before I surrendered. If you're patient and willing to learn, then go 'as is' - but best to go in with a hobbiest mindset and not for huge gains.

Honestly, I think the s9 is a decent buy, even for the refurbished one. I learned a lot and this winter I mined upwards of 23k sats.

Keep in mind that they are old machines so they might get bonked-out for one reason or another and need a repair. Also, the fans might drive you crazy of its in your house. Mine makes a ringing sound that carries through the wall into the next room, even with the modified 'quieter' fans.

Good luck!