Merchant: The Bodybuilder
This simple shop is full of glass jars in many different sizes and shapes, each and everyone containing teeth. The labels on the jars display every kind of animal one hat ever heard and a few which do not mean anything to you.
A minotaur sits behind a table which seems to small for him. He is hunched over the flat surface, a mirror replaces his left eye, and with delicate and neat movements he strings teeth onto a thin cord.
The Bodybuilder sells necklaces made from teeth, each especially made for the customer to his specifications. Upon death the necklace crumbles and forms a new body which the soul can immediately inhabit. This body is always chimeric, depending on the teeth used in the necklace.
The Bodybuilder requires all teeth of the customer and often sends them on errands to replace teeth which are running low in his shop. These quest are seldom easy and always dangerous, and the more rare the teeth the customer requests are the harder the quest will be.
Merchant: The Wishmonger
This cart is quite ramshackle. On the front is an empty counter, while in the back many different surgical tools can be seen, all neatly maintained and shiningly clean.
The proprietor of this cart is the Wishmonger, a bored looking Drow. From time to time he speaks (at normal speaking volume) into the passing crowd, also sounding bored: "Wishes, big and small, to improve yourself. Perfect for you and your friend".
When a customer shows interest in his wishes he informs them that he can only provide wishes if one comes with a partner. If two people show up, he asks them what improvement they want to make. Depending on their answer he tells them his price. Upon receiving payment the Wishmonger creates one Wishbone - a bone with two hooks, one on either side. He tells the pair that they have to break the Wishbone together to make their wish come true.
If big improvements (increase of status values, greater changes in skills or great increase in HP, etc) are requested the prices are more steep. The Wishmonger tells his customers that each must give one bigger bone in their body. For smaller wishes smaller bones suffice. He assures his customers that the taking of the bone will be painless and that upon fulfillment the bones will be returned.
No one gives away wishes for seemingly no cost. As soon as the partners break the Wishbone they both roll 1d20 (each) to break the Wishbone. The person with the higher roll holds the larger piece of the bone and gets their wish fulfilled, while the improvements in them are subtracted from the person with the lower roll. Both get the bones back from which the Wishbone was created.