I've used Top End Interiors before...they've done alot of well known cars down this way.
I'd expect trim only to start at 3k.Maybe double that if foam stuffed..................full interior might go to 10k-12k sometimes more for front seat frames.
Devonish seats go for more than expensive scheel frames or same era recaro modified to look like brock or esp scheels.
They're on facebook..just done gts-r seats