I am working with one of these dilution refrigerators of Oxford Instruments in my PhD thesis (not directly quantum computing, but a related topic in the direction of quantum computing). They are an incredible piece of machinery, with the push of a button they cool down your sample from room temperature to about 20 mK (admittedly, it takes ~30 Hours). That's 0.002 degrees above absolute zero.<p>I wonder how much of the 500k$ is really the material cost. As it was said in the article, the Helium-3 gas is already 40k$. And there is a lot of high-purity metals used: gold-plated oxygen-free copper for the main parts, silver wire for thermal anchoring and heat exchangers, indium wire for vacuum seals etc.<p>And thats just for the cryostat. To really use the cryostat for quantum computing experiments, you need to buy all of the cryogenic high-frequency electronic stuff. The cryogenic cables mentioned in the article by Coax, Ltd. are indeed really really expensive. Our last batch of NbTi-NbTi cables (i.e. superconducting inner + outer conductor) were about 1500$ per meter. Cryogenic microwave amplifiers (they operate at ~3.5 K to reduce microwave noise) cost about 5000$ per piece. Microwave circulators run at about 1500$ per piece. (According to the google paper, they used 9 cryogenic amps and 45 cryogenic circulators).<p>It's really very fascinating. But on the other side, I guess there is just not enough demand to justify founding another company building these fridges or superconducting cables. Unless of course at some point you manage to build these systems in large scale. But right now, that is just not feasible because it's no plug-and-play system. You have to constantly adjust and recalibrate the electronics to make the chip work.