"Guy Byars" wrote
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?

Your best bet is to check out a flymarket at a large fly-in - Oshkosh
and Sun&Fun are good options, but somethign more local may also work
for you. For example, I paid less than $100 for a used TWA walkaround
bottle - basically a bottle with strap and mask that was used by TWA
crew to move around in the event of depressurization. You might also
check out Ebay for something similar.

Michael