VACExtender design for less?

I’ve seen a metric ton of extenders on eBay. All of them either have the noose or the strap. It seems like $100 is a steep price for a modified vac extender. Is there a less expensive way to alter an extender?

I don’t think I would pay $300-400+ for some of those on the market charging that price but consider $100 for a well made functional copy to be a proper value.