I use a variety of materials for jigs, and yes, things are getting costly. I've always tied a lot hair & feather jigs, but also make jigs with silicone & rubber skirts. I get those materials where I can find them, and I'm buying the skirt tabs by the 100.
All of the silicone or rubber skirt materials now, in the entire world, are being manufactured either in China, or Vietnam, so that's created a supply issue.
You can find some material in cheap bungee cords, ( Harbor Freight type stuff) but the colors are generally going to be limited to either black or white, and of course you have to cut them apart. It's the same material as Living Rubber.