He needed to implant the idea in such a way that Mabuz felt he was doing it of his own volition, not that he was being persuaded to do so. When someone committed acts in which they firmly felt they carried out the decision on their own, they tended to over commit in some regards. Having Dr. Mabuz "over commit" to giving Farren a percentage of his earnings was something that he firmly supported. After all, more money was never a bad thing, and it would help put Farren back on the track he'd fallen off of as a result of his incarceration.
With the request in hand, Farren made his way to the mysterious magic shop that Dr. Mabuz largely made use of as a front for his other operations. Research and development of a nefarious nature took place behind these walls, and this was almost entirely known by all that lived within Oak Town. Yet, with how corrupt this town actually was, nobody ever felt safe enough to actually do anything about it. Though he didn't look it, Doctor Mabuz had the support of many the big players that resided in Oak Town. It was very hard to do something to the Doctor without creating some sort of domino effect - which was largely why Farren was so much against using force in any sort of manner when it came to his dealings with the Doctor - manipulation being the best course of action when dealing with him.
As he arrived to the shop, the good doctor seemed to have already been waiting for him at the door. He had a look of annoyance on his face, of which Farren could only assume the doctor once again felt he was tardy. Like always, the Doctor had a perception of time that nobody else in this world could grasp. Even if you arrived twenty minutes before the time of a meeting, you were still considered "late" in his eyes. Farren could only assume this was because if the good doctor wanted something, he needed it to be available in the same instance in which he desired it - showing up a second later than that was unacceptable.
"Here. I need you to deliver this to parcel to Castle Phantasm. It is of the utmost importance that this delivery arrive promptly and undamaged. Inform the guards that you're making a delivery and they'll let you inside. Understood?"
WC: 505
TWC: 505/1000