I tried making napkins from some Christmas fabric for my daughter.
It was "quite" the experience - I think I tried making a 1/4 inch hem on them. I did not enjoy doing it.
So - as far as how much to ask - I have no idea. I know it took me a looooong time to hem each one of those napkins. But I am a slow sewer.
Maybe cut an 18 inch square of light weight cotton and hem it and see how long it takes?