Lex exited the Mystery trial 8 hours later, finally having completed the trial. It was a genuinely interesting experience, and he learnt a lot. Moreover, he would call the 'reward' anything but small or insignificant. Although he had yet to try it out, he gained a 6th sense for detecting people's emotions in reaction to something he said.
Well, to be fair, the actual 6th sense was very vague and weak, but it was drastically amplified by Lex's intuition. But even without the gift, Lex had gained a whole new perspective about his ability to influence people with his words. In the end, he had completed the trial by convincing the Game Master that the only way to actually prove that he was motivated by purpose was to break his own rules and set them free.
He had tried a few other tactics which did not contribute towards the trial, but did provide him with unique experiences. After all, he would never harm an innocent person in real life.