On a trip last week, we flew for 3 hours at 10,000ft. Afterward my wife
complained of fatigue and at times during the flight she complained that she
couldn't "get enough air". I am thinking that supplemental OX for her would
be helpful. I checked the Aerox systems and the other systems, but they
seem pricey.

Given that this is a comfort issue and not a safety issue and is only for a
passenger, are there any other cheap portable OX systems available. Medical
systems perhaps?

GB