Qarth's citizens are a wealthy bunch since their city is a massive trading hub for goods from around the world. These people know the value of a dime. And of dragons. Check it:
Xaro invites Dany to live at his mansion in Qarth, all the while bugging her to marry him. Jorah eventually discovers a Qartheen wedding custom where the spouses may ask each other for anything they want and the spouse cannot deny the request (41.Daenerys.84). Eventually, Xaro just flat out asks her to trade him a dragon, but Dany still refuses. He gives her the boot (64.Daenerys.18).
Quaithe is a mysterious woman in a red lacquer mask. She offers Dany advice, but it's the not too helpful type of advice that's all twisted in riddles. For example, "To go north, you must journey south. To reach the west, you must go east. To go forward you must go back, and to touch the light you must pass beneath the shadow" (41.Daenerys.69). Quaithe claims she offers only the truth… but would it hurt her to unlock the truth from her riddles?
These rulers of Qarth come from ancient lines of kings and queens, but the rise of Qarth's merchant class has caused them to lose political clout lately. They must now complete with the wills of the Ancient Guild of Spicers, the Tourmaline Brotherhood, and the Thirteen (41.Daenerys.18).
Pyat is a warlock and servant of the Undying; his goal is to get Dany into the House of the Undying. Outside, he gives her directions for traversing the house and feeds her shade of the evening, "the wine of warlocks," a.k.a. the LSD of Essos (49.Daenerys.24). He also gets a wee bit upset when he sees Dany and Drogon burning the place to the ground.
A group of ancient, undead warlocks, they want Dany to join them in the House of the Undying. When Dany enters, they show her many visions, some likely events of the past and future. While she is under their spell, though, they attack her, for they "wanted her, needed her, the fire, the life" (49.Daenerys.77). Drogon saves Dany by lighting their ancient corpses on fire.