Jeff’s Bronco Graveyard has them, but the price is even higher.
https://shop.broncograveyard.com/mobile/1980-1986-Ford-Bronco-and-F-Series-Truck-Heater-Blend-Door/productinfo/37282/I could see it justified if it was a steel hinge upgrade, but it’s just another plastic flap that will break.
SHORT BED 4-DOOR DIESEL: 1986 F350 4x4 under construction-- 7.3 IDIT ZF5+GVOD
STRAIGHT SIX 4X4: 1981 F150 2wd to 4x4-- 300 I6 close ratio diesel T19, hydroboost brakes, Saginaw steering
BIG F: 1995 F-Superduty under construction— converting to 6.9L IDI diesel ZF5+DNE2