Dbl blessed wizards hat 5-10 mill usually.
Its best to refer to the gorget as just "Made By," since calling it dbl exceptional just gets confusing. It is dbl exceptional certainly, but the [Exceptional] in brackets is different than the normal dbl exceptional. Made by and Sewn by have a collectible quality to them, but its very name based so you'll see pieces priced from 2 mill to 15+ if the name is something special.
It can be difficult selling the individual armor pieces though, since collecting a complete set of Made by or Sewn by is exceedingly difficult.
Hope this helps.