I think that would be an incredible bargain~I am sure she would too. She obviously wants them pretty badly since she's asked for them several times.
I was thinking I would charge $2 each, or maybe 3 for $5. If I wanted them, I would still think that was very reasonable for a handmade scrubbie.
I am sure she'll be happy to pay whatever you charge! Good luck, I hope you post pics of the finished scrubbies! They sound very useful