It’s mostly cosmetic. What kind of image do you want to portray? If you run a breaker’s yard, then storing parts in a Grade B or Grade C container may be perfectly adequate.
If you’re the manager of a prestigious company, however, and your containers are to be stationed at head office for everyone to see, then new (1-trip) or Premium quality containers would probably be more suitable. Please get in touch if you’d like to know more about how we grade our used containers.