+- 3.5k or so. The shop I was at got one back in February. I loved it. If you are already using a smoothing screen with success - you will see marginal improvements. It really shines as a first down to smooth out unruly fabric. Or, if your fabric is really rough, this is when it beats the smoothing screen hands down.
I was happy to have the Hot Head and we used it often. But depending, it can be situational.