I charge more for french as well, but only 2.50 more as its takes me longer but I also use more product. I do: 1 base, 1 negliglee, 1 cream puff, 1 negliglee and then topcoat. That way they still have the sstrength and they look very natural with a thin coat of negliglee over the white. However it someone wanted brighter whites I would still do 2 negligee then 1 white, then topcoat.