Pardon the ignorance but what's being exploited by someone buying a video game character?

If you buy someone's old gaming account (Steam for example) with many years of activity, you can appear more legitimate when trading, therefore making it easier for people to trust you and fall victim to your scam(s)

I think he was just saying that it is similar business to that. Just drawing comparison that there are a market like selling video games accounts. Also usually people who cheats in games will buy high level accounts because they will be banned much faster if they start playing with new accounts for cheats. This happens in some of the games I play all the time.