One can forget that. It is extremely expensive, only richissime people can afford them. 600€ per
day!! It's not a plastic chamber like the one some forumers bought, it's a professional chamber, like the one Yas showed us. In fact, they provide (sell or rent) it for clinics, hospitals, or research centers, not for individuals.
But, here is a tip. In our country, we have the social security (CPAM), to which we contribute since we were 18 yo, even if we were students without any income. So, it's normal that today you benefit from it. Your CPAM will pay for HBOT sessions if it is indicated (officially) i.e. if you have a medical receipt. So, you can try to get a receipt from your doctor and go to the center the less far from your home.
Here is a pdf where you can see, page 13, the official indications, and the french towns (also in overseas territories) :
Let me know if you think your doctor won't give you the receipt (if you're not eligible).
I had another idea: the company who sells it (it's a plastic chamber, like the Macy-pan or the Zoy's, but french made product) to 7000€. What if I ask them for a discount if we can do a bulk purchase (achat groupé)? How many people will be interested? (also in other european countries, I think delivery will not be a problem for them).