I understand that. Amazon won't let you price your books for less that it costs to print and post. I know.
I make most of my sales though kindle, so I don't worry about it so much.
I'm very impressed with your, "pay what you want" strategy. I think that is great.
Get the audience. Build that following.
My tuppence-worth is exactly worth that.
I just get frustrated that self- published authors aren't maximising their income.
It's a tough school.
I'm in the same boat.
All the best
Malky