I don't think any spot seller can get away with selling one spot to 30 people. 2 days ago, I and my bf were the ones who were right behind the big group of spot sellers who apparently arrived at 1am to get the first spots. When we noticed that this woman is trying to sell her spot to multiple people, we objected immediately and said she could sell her spot to 1 person only. Then we were joined by multiple people behind us (basically anyone who could speak English and understood what was going on would speak up and agreed that spot should be sold one for one only). We all took photos and videos of what the original line was and told the sellers we would report them to Hermes security. Up to a point, many of us were saying "one for one only" together which showed this awesome unity. These resellers are very stubborn so they kept trying to argue but when multiple people spoke up together, I think that had a very good result. At 9am when Hermes security started policing the line, some people who had taken photos / videos reported the situation. And to everyone's cheer, the chief security guy went to each spot where multiple people have cut in and gave them 2 options: "Either you leave the line or you all come in and none of you will get an appointment!"
What I learnt after this ridiculous ordeal is that if people unite together and all speak up against anyone who try to cut in line or resellers selling to multiple people, the problem might be resolved.