"We have mages on our team, and we also have wind spirit orbs, but this time the dungeon is bigger, so we swapped them out. Is that bad?"
Better be honest about this.
"No... no problem. No rule says adventurers have to pay for all the items they bring back from dungeons in the guild. Even for items, the guild will buy them at the highest price... safe... I'm just saying. that's why I'm free to complete the quest procedure and not submit items, and I'm free to exchange them for what I have. There's a value for each size of spirit ball, and the number of completions will change, so I checked. If you accept the quest to become class B+, and the spirit orbs didn't grow that big, poor adventurer. After all, the difference in rank will double the amount of the reward, so there's a chance there will be complaints."