Ok - so...with my first, I didn't purchase a pump. I used the hospital one for the first several weeks for free because of my massive engorgement issues and then was able to borrow a Medela PIS from a very close, very trusted friend. I knew the risks of milk backup because it was an open system, but I also felt relatively safe because I knew her health history so well.
Now, with DD, I did buy a pump - but I bought one used from someone I don't know. I bought an Ameda Purely Yours double electric, but I purchased a completely new Hygeni-Kit - with all new parts - so the only part that is actually being re-used is the base.
I bought it assuming it was OK to buy used, because it was a closed system. Then I was told afterwards that even that isn't OK. I'm very confused as to why. I haven't used the pump yet (DD is due on 5/13) - so would like to get some clarity to this before I need to use it.
TIA for your help sorting this out.