Should you ever find yourself in a fairy tale, try your very best not to become a merchant (tailors and traveling soldiers usually have better luck). Should you find becoming a merchant unavoidable, avoid having any daughters. Should daughters arise despite your most strenuous efforts, never bring them any gifts when you go on a long trip. It will inevitably prove fatal. Making promises in a fairy tale only ever ends in heartbreak, child abduction, or transfiguration. And what’s the return on investment? A single flower? Enough rampion to make a few salads? If you’re going to trade your most beloved child to a witch, make sure you’re getting something equally valuable in return. Learn from the mistakes you’ll read here. Negotiate aggressively. Why not ask for a magical oil can that never runs out? Or your daughter’s weight in gold? Or a wishing ring? Remember, you hold the most important bargaining chip of all: your precious daughter that an animal wants to get married to.

The Promiser: The traveling father in “The Singing, Springing Lark”
The Promise: To give the first thing that greets him at his front door to a lion.
The Catch: It’s his youngest daughter.
The Return On Investment: Not too bad. His daughter marries a lion, which later turns into a dove, but then even later turns into a prince.

The Promiser: Rapunzel’s father in “Rapunzel”
The Promise: Anything the witch asks for in exchange for all the rampion he can carry.
The Catch: The witch asks for his unborn child.
The Return On Investment: Unknown. He never sees his daughter again, but whether or not the exchange was worth it depends on how much rampion he can carry.

The Promiser: The Princess in “The Wonderful Sheep”
The Promise: “The Wonderful Sheep” is “Beauty and the Beast,” but with a sheep; the princess falls in love with the enchanted prince and promises to marry him just after she gets back from attending her sister’s wedding.
The Catch: She loses track of time and he dies from sorrow waiting for her.
The Return On Investment: Terrible. The last line of this story is “Even princesses are not always happy.”

The Promiser: Beauty’s merchant father in “The Beauty and The Beast”
The Promise: To bring his youngest daughter a single rose as a gift after his latest journey
The Catch: He snaps a rose off of the bush in front of the Beast’s castle; the Beast demands his daughter in exchange.
The Return On Investment: Not bad for Beauty, but not great for her father; he never sees his daughter again.

The Promiser: The miller (and later, the miller’s daughter) in “Rumpelstiltskin”
The Promise: That his daughter will spin straw into gold if the prince marries her; that she will give Rumpelstiltskin her firstborn child if he spins straw into gold for her
The Catch: She can’t actually spin straw into gold; 
The Return On Investment: Excellent; the princess is allowed to keep both the gold and her child. Extravagant promises can work out, if backed by a web of elaborate lies.