I don't want to just throw it out (well, actually, I have 3: 2 manual and 1 double-electric)....but I know there are hygiene issues.
I offered mine to a La Leche League Leader to give it to anyone she found needs one but can't afford it, and she took it.
Actually, I had to call several La Leche League leaders, in more than one county before I found one that would take it.
The first problem is the worry about the hygiene issues- a leader told me that LLL rules prohibit this. But there is a great deal of variation over this from one leader to the next. Some leaders strictly adhere to the rules, and others don't.
The second problem is if the pump is made by Medela. I have heard from a couple leaders that LLL has a rule that boycotts or blacklists Medela or even the mention of Medela in meetings. I think it is because they make bottles. Again, some leaders follow this rule, and some leaders don't.
If you call enough leaders from enough different LLL groups, eventually, you should be able to find a leader who will gratefully accept your donation of your unused breastpump.
I also had three used pumps. I gave one to the wife of my cousin, and the other two to my sister.
FTR...I don't want to sell these (1 Medela, 2 Ameda). It just feels like a shame to put them in the trash, especially the double-electric Ameda pump which was barely used. I boiled all the parts to make sure I got rid of yeast, but even so, I understand some mamas might have reservations about used pumps.
Thanks for the suggestions mamas. Off to look up Freecycle and LLL groups.