removing enchantments if at "too expensive" stays at "too expensive"

I had a sword I enchanted to the point when trying to add a new enchantment it said it was too expensive. I thought I could "strip" all the enchantments and start over by using the grind stone. It strip the enchantments but it still says too expensive when I try to add any new enchantments. So now I have a sword that can't be enchanted with anything.