Aaron has no idea about what is happening in the world. He has no idea that someone of his generation was in the same situation as him.
When he saw that he was the hundredth one to reach Uncommon Grade, he just assumed that all ninety-nine belonged to the older generation. It was not easy to get so many SPs.
There are Skill Point Stones as an alternative, but who in the world would do so? After all, there was no mention of any information about rewards from the system or this upgradation.
Moreover, if this information is classified as secret and restricted, then someone from his generation could not have access to it at this time.
The thoughts of Aaron and Mary are more or less similar on this point.
If not for Mary's master Serena, she couldn't have reached the Uncommon grade and Aaron, without his talent, wouldn't have reached the Uncommon grade.
Situations like this are unique.