Chinese fiber lasers that can cut thin stainless sheets are around $5K now.
I've been making stencils from mylar sheets on a CO2 laser cutter -- the trick is to ablate (etch), not cut away the mylar to get crisp edges with no bumps or burning.
When the laser was down and I needed some quick stencils I got a cheap craft vinyl cutter and it also made surprisingly useful stencils (the trick here is to overcut the corners so nothing dangles or leaves a little nub).
Haven't got around to trying Mylar on my 40W yet but etching works well on light card and paper. I will run some tests on cut vs etch when I get some thin plastic loaded up.
Still amazed how often people ask can xyz small laser cut 'metal' even Google knows the answer to that one.