Inogen

[1980Mooney]

On 6/11/2025 at 12:07 AM, Utah20Gflyer said:

I bought mine off a local classified ad site called KSL.com.  Similar to craiglist.  I’d check whatever you have in your area and see if you can pick up a used one.  I paid 400 for a Inogen G3 and then spent another 100 replacing the cylinders in it a couple months later.    There are lots of people who want to sell them after their parent passes or they upgrade or get over something like Covid.   
Performance is very close to the G5 at a fraction of the cost.  

 

13 hours ago, Will.iam said:

craig's list. Instant if you go pick it up and cheaper price too.  You can always send in the unit to aftermarket places to get it overhauled when the filter's wear out.

 

12 hours ago, Aaviationist said:

All over Facebook and OfferUp are concentrators and compressors. Get a set of those and just fill your own bottle. 
 

Will be way cheaper and you can help your friends out that way. 

Just be careful if you are attempting to buy a used one online rather than local and in-person.  And even local and in person there are pitfalls.  Due to the price and lack of availability, these are favorites for online scammers. 

The Inogen G5 and identical OxyGo Next were introduced in 2019.  I searched OfferUp, Mercari, Craigslist and eBay (they sold them at the time) back in 2021. There were a considerable number of what appeared to be legitimate lightly used units for sale at the time.  I spoke to a couple individual sellers in New Mexico and Colorado (natural markets due to the high altitude) that advertised on Craigslist that seemed honest and legit.  I ultimately found a lightly used (about 120 hours) OxyGo Next locally in Houston on Craigslist for about $400.

I have searched again recently looking for a second one.  I added Facebook Marketplace to the sites.  The market is different now

1. eBay will no longer sell full portable units.  It is because what @Marc_B said above - the FDA classifies this as needing a prescription.  If you post a unit on eBay, it will be taken down by the moderators.  Yes they sell parts and accessories.
2. There are "bait and switch" scammers online.  On OfferUp I called a seller and they said the "portable in the ad has been sold but I have a stationary 120 volt unit I can sell you".
3. The condition could be crap.  Get visual confirmation of Total Hours Used.  I found a local G5 recently with 15,000 hours on it.
4. On Marketplace, I contacted a seller in Texas.  They sent video of the unit and seemed legit.  But then things got weird and ultimately they could not provide evidence of shipping.  PayPal reversed and refunded my payment.
5. If you find one locally being sold by relatives of someone who no longer needs it, be cautious if it has been sitting for a long time (like years).  If the relatives left the battery installed in the unit sitting for months/years, it will likely be fully discharged.  The Inogen/OxyGo batteries are LI-ION.  Fully discharging a lithium-ion battery is harmful and can cause irreversible damage. They may be shot. (There are a lot of shot "used" batteries for sale on these sites).   The batteries used to be ridiculously expensive but prices have come down.  Some places wanted $680 for a 16 cell (double capacity) battery in 2022-23. They are about half that now, but since they are made in China are probably going up.

Buyer beware.....

[Aaviationist]

Oxygen generators and compressors are easy to find on Facebook. For under 1k you can have everything you need to fill your tanks yourself including all the fittings and adaptors. 
 

it’s not hard. I do it and I know about 10 other people that do it. 
 

id take a tank over an in flight generator any day. 

[donkaye, MCFI]

26 minutes ago, Aaviationist said:

id take a tank over an in flight generator any day. 

Why?