No, that's economics. It's not a matter of how many years the valance panel has been out, it's a matter of how many they need to sell just to break even. And there isn't ANY company that's in business just to "break even".
On a low demand part (be honest with yourself- how many people are actually going to be buying the part? These aren't Big Macs), it could take decades to recoup costs- so just be glad someone was willing to take the leap at whatever price. If you don't like the cost, break out a hammer, a piece of sheet metal and make your own; it's what you'd be doing if nobody reproduced the part anyways.
You think you've got it bad? Buy a Studebaker.
