"Dan" wrote in message
...
So short of doing your own transfilling, where does everyone get cheap
O2? Or are you paying big bucks at the FBOs? For an occasional user,
the transfilling equipment does not make sense.

An Oxygen optimizer (i.e., Mountain High or Aerox) makes your tank full of
O2 last about six to ten times longer than a normal system. Filling your own
and an Optimizer brings the cost of O2 down to near zero. Further, it makes
it worthwhile to use higher altitudes that an expensive system make
prohibitive.