Is it the plastic button that has broken or the metal stem? If it is the metal stem, then the main PCA board has to be replaced. The repairs are much less than buying a new one. You can call DME Solutions for repairs if you choose. Their number is 719-592-0333.

There is a couple portable concentrators made by Respironics. They are called SimplyGo and Evergo. One thing to keep in mind, if you travel by plane, you must have a FAA approved portable concentrator. The Sequal Eclipse is also a good one.

If you cant find a person that wants this(not sure why you wouldnt), then you might want to look into a non profit organization to donate to(you can write off your taxes). I have one near me that provides medical equipment to people that cant afford it. They need alot of donations to provide to less...

One thing to think about. If you modify the machine in anyway and you have to send it into a manufacturer or repair shop, it will cost you more money because they will replace that part that you modified. Or in worst case scenario, wont fix the machine at all.

Do Not use WD40 on the buttons as it leaves a residue that will contaminate the circuit board over time.

Do Not change your settings without consulting your doctor. There is a reason that the instructions for changing the setting are not put into the user manuals of cpap/bipap. Changing settings can be harmful to your health.