I talked about this earlier this week, about Magnus being (as usual) a complete and utter jackass. However, I want to talk further about how not only makes him look like not only a sociopath but why this was a stupid move on his part.
First of all, no one told Magnus that he had to come himself. Actually, it would have made more sense for him to just delegate it to any of the warlocks under his command. To be honest, Magnus is supposed to be High Warlock of Brooklyn. Yet, I have to see any hint of him carrying out any of those duties or even mention conversing with any warlocks under his reign.
So what else does Magnus have to do with his time? Also, if Magnus was so worried about being paid, he should have told Jace and Alec from the get-go that he was going to charge for helping Luke and Maia. Magnus waiting until he was finished helped the werewolves make it look like he was trying to be shady, and since this Magnus, I wouldn’t put it passed him.