I think the used market is a good measure of the worth of something. After all the hype and incentives are gone you are left with a thing that will only sell for what someone is willing to pay for it.
I wish the used market sites would post the actual price paid when the deal is done. I'm pretty sure the "asking 1/2 of retail" is almost never paid. I'd guess 20-30% less than the ask is what the deal goes down for.
A quick look at Hifi Shark shows these speakers don't sell fast and the ask is the typical 1/2 or MSRP. Slow sales = price drops. Especially when the seller has to sell by a certain date.