DW has a mild case of COPD, and does not do well at altitude. In fact when we were in Taos, at 7000 feet, her oxygen level dropped.
The other problem, is cabin altitude on an airplane is between 6000 and 7000 feet. This causes a problem for her.
Another issue is that one of her sons moved to Nevada, and if we want to drive up to see his family, the passes are over 7000 feet, no matter which route we take.
Thank goodness, she is not seriously ill, but Medicare requires the oxygen level to be 88% or less before they will buy a concentrator for a patient.
I spoke to Inogen, and they offered a $1000 discount on their newest model.
We had to jump through some hoops with a pulmonologist, but we got the prescription.
Total cost for a G5 concentrator, cables, battery and case was $1500. We added a double battery and a backpack for another $500.
IMO, it was money well spent.