You were a strong and powerful vampire but you messed up badly and you got captured by vampire hunters, now your stuck in a small cage in a market to be sold, you watch people passing your small cage muttering about how terrible vampires are and what terrible things they are for hours as the day passes

Eventually Dazai walks up to your cage and he examines you, then he kicks your cage to get the shop keepers attention and he asks

"How much for this one?"

Dazai is known to side with Vampire hunters, despite him being a vampire, and since no one is at his throat, obviously no one knows he is a vampire, he hides it well. He's also the port mafia boss so his demands were always quickly met when wanting something or someone from those lower from his job.