Maybe I Just Wanted A Souvenir From P-Town
Whoa hold on there half-orc. Clarification. You realize that you don't yet get the +1 WI, you only get it after you kill Andicorn the Unicorn King, make a paste out of his horn, there's like a ritual or something you have to do. Grettin and Shettin didn't just jack up your WI right there. I'm pretty sure you got this, but your post is a little ambiguous.
But yeah, 500 gp for horn, sorry, I forgot about that.
Cinder, Mike digs the necklace. In fact, he goes out and gets one for Abby too. Then he realizes that she doesn't have a neck, and spends a bit more $$$ to turn it into a tiara. Where'd Mike get the $$$ you might ask. He's a 4th level zombie thief don't forget.
Yeah, maybe the thing isn't worth 20 gp, but then again, I've got a shirt I paid $60 for when I was in Provincetown? It's this thin crappy blue shirt, almost like a baseball T, and it's probably worth about 5 bucks. And I never wear it. I don't know why I bought it. But there it is. If Chicago and Boulder had a baby and it lived in the Grand Canyon, that'd be what Durth is kind of like, and so there are expensive boutiques. It's sort of like Salvation Army-cum-Hot Topic, where you found the necklace. There were a couple goth kids shopping for cloaks and a guy with a Misfits hairdo at the counter. You figure he probably wouldn't even care had he seen you take the necklace, which there's no way in hell he would have with that 5% roll.
Okay Cinder, you buy some potions and a lead box, because Brogg had the cash. In real life, a lead box is probably the last thing you want to carry around, but I guess adventurers regularly do things like cart around 10 days of food and water, dead bodies, 10 swords and crossbows they took off the bandits, all kinds of feats. So it's cool.
Cinder, you go ask the guards about Vrill. Good thinking. Lar and Abe tell you that they didn't see anyone else, but at the upper entrance, the Detect Invisible alarm went off, which is why they were down in the caves in the first place. They thought you were the guys, come back to nab a zombie. But the intruder was never caught... maybe he was your guy? If you check with the Potion Guild, they have record of one Master Vrill being formerly in charge of the Grito guild, but after some big scandal a while back, the place was closed and Vrill disappeared. Strangely, this was around the time that Durth's own Master Yves Meifer disappeared, 100 gp reward for any information about Meifer.