Ultrasound enables espresso-strength coffee brewing in 2–3 minutes at low temp

How much would such a device cost?

I think the biggest bar to having an espresso machine is that a good one is hundreds of dollars. The control device in this experiment (Sanremo Cube espresso machine) runs nearly $3,000.

You don't have to spend that much to get very good espresso, but under $1,000 you're making real compromises. Can you produce ultrasound coffee machines for, say, $300?

y'all've been yapping about this for half a decade and I still can't buy it

edit: I was thinking of cold brew actually but my point stands