A sign-maker could make these stencils for you from your artwork. They have systems that are basically plotters with a razor knife in place of the pen, and can cut out anything you can draw (by hand or computer). Of course, just like a hand cut stencil, it has to be able to be cut w/o a 'floating part' (a circle in a circle would be left floating), everything needs to be connected somehow.
I have no idea what they would charge, but it's all pretty automated, so maybe not so much? And you could do lots of variations in one shot. Set up would be about the same whether you had one design on a sheet, or multiples, so I don't think price would be much different. I imagine cost is based on a set-up fee, plus total area of contact paper, and probably inches that the knife would travel. But that's just an educated guess.
PS - They are awesome looking! Maybe I'll ask for a kit like this for Christmas!