hand-sewn liners for my eye masks

I am making washable liners for my eye masks.
I happened to think of it the other day when someone asked how they should wash the eye mask.
Well, they are not washable, but can be spot treated.

So, I am now sewing by hand some liners out of white cotton vintage fabric so folks can keep their eye masks it new condition in case they want to wear them while they have eye makeup on or they are sweating from a fever...

These things are almost as much work as my eye masks are - LOL

I think I will offer them separately to keep the cost of the eye masks down AND then they can buy extras of the liners too if they want them.
They will be around $7 or $8 - should be more, but I'm trying to keep prices down wherever I can.

I also think that if someone buys a set or spends over say $60 or $65 with an eye mask included in that purchase, I'll throw in a liner for their free bonus instead of something else.

What do you think ?