Oh I just thought of something else. This is assuming that it’s a stick-on device and nothing implanted internally - but if it’s undamaged, it’s just come off and is no longer sticking - maybe in an emergency you might be able to reattach it with some non-latex false eyelash adhesive. $200 is a lot of money per pop.

If you apply it very thinly and let it slightly dry to tackiness it might even peel off somewhat cleanly afterwards (never tried it on shaved fur).

Even a bandaid? Adhesive skin tape would probably be far too aggressive as cats skin is thin and fragile.

Places like Vet Shed online have non-adhesive bandages of material that sticks to itself only, to hold it in place. (Maybe diagonal going under one front leg to over the other shoulder if a figure 8 would put pressure on her neck.)