Early A body door sills

I can only find 2 vendors that sell reproduction door sills for my 64 Dart GT. I have reached out to a company that makes many door sills for various classic cars. I cannot understand why A body car door sills are priced twice the amount of other Mopar varieties. The only vendors that sell reproduction are Classic Industries and Laysons. Does anyone know of any other sources?
Bought mine at Laysons. They were nice. It's all a numbers game. Not enough call for multiple manufacturers to make them. At least they are repopped.