I would check with UHMS or NMDHMT for data on this. Where I work Hyperbaric medicine is only half of the game, with wound care being the other half. The docs I work with make considerably more than 120-140, but they both often put in 70 hour weeks.
I've always thought that it would be a nice side gig in addition to an IM practice ( or EM, if the hospital will go for it, like ours did). Aside from the education part of things, the docs are in one half of the clinic seeing wound care patients while the Hyperbaric patients are getting treated (both generating revenue at the same time.) The only typical involvement with an average HBO patient our Docs have is a weekly or q10day visit. And they must be on campus while HBO is in session.
Feel free to PM me if you have other questions.