Numb,
To answer your question about my pain levels, I am able to keep them at a minimum with a series of dives and a few maintenance dives. A duwer( do-er) of oxygen cost about $150.00 and burps off into the atmosphere at about 1%per day. So when you have Oxygen, you use it. The amount I paid, I will tell you privately, as I said before, more than most would want to afford. Drop me an email. I believe it is on my profile. I'll tell you this, more than a brand new Cadillac.
All the best..Diana