No offense brother, but having bought your bolt and barrel from completely different places and manufacturers, the charges for shipping and matching them aren't really undue. Fulton has no way of guaranteeing fitment and headspace with everybody who lays claim to building off a specific pattern or specification. The way I see it, they are still offering to resolve your problem even though your headspace issue isn't necessarily of their making. As a business person it would only make sense to charge a fair and appropriate fee to match another manufacturer's bolt to your barrel. You need to speak with the manufacturer of your bolt, as it is likely the responsible component. FA has an excellent reputation for the quality of their product, and it is likely that their assumptions about your issues are correct.
Wishing you luck brother, it's never fun to iron out the wrinkles, but it always feels good to resolve it and fire those first rounds through a fully functioning weapon. Keep us posted on how things work out...