I don't totally understand it.

With trusted trade partners with good reputation points or trust feedback or with VIP, expert, and special badges, you can have more reliable trades. It is very rarely to see such trade partners will scam you. Almost no. I agree with you with this part.

However, what is lower transaction fee? I don't understand that part. As I know, exchanges or Peer-to-peer exchanges will charge you fix trading fee which is in percent of your trade value. Your trade partners no matter they are newbies, VIP or trusted ones, don't affect transaction fee or trading fees of your trades with them.