Here you go... right off a google search and back to FABO
No sale at $400/pr just a few months ago:
[FOR SALE] - NOS 73-76 Duster Rear Tail Light Lens NIB
Here's one for $99 and I don't think it sold in 2019:
[FOR SALE] - NOS 1973-76 Duster right tail light lens 3679246 He referenced one at that time on ebay for $199. Shows you can't always go by ebay's dreamer prices.
They might be getting ready to make this repro soon through OER (Classic Industries) for $179. That can hurt NOS price. Or maybe help it??
OER 3679247: 1973-76 Duster Fastback - Tail Lamp Lens (lh) - JEGS