Check with local medical supply places. I've tried a couple places, everyone wants it free. Again, I wish I could donate it, but my mother is now on a fixed SS income.
There is free and then there is “free.” My suggestion would be to contact a local major university Mechanical Engineering Department. Many of them have engineering design capstone classes where engineering students build medical devices for people who are handicapped as a way of combining theory with practice. Tell then what you have told us, that you want it to go to a veteran, but you need to get some value for it.
Large Universities are good at doing fund raising for students and student projects. Also they can offer tax benefits for donations and help value things. While you might not get top dollar, you might get enough in charitable donation tax benefits, and some money to make it worthwhile.
Good luck.