Negotiating with a 3 year old

Now I know you are not supposed to negotiate with your child but for kicks one night I tried to strike up a deal with Caleb. I asked him if we could trade jobs - he washes the dishes and I would pick up his toys. Here's how the negotiations went:

Mommy: Caleb, why don't you wash dishes and I will pick up your toys.

Caleb: But, Mommy, I am too small.

Mommy: Are you sure you can't wash the dishes?

Caleb: (pauses and thinks) I know Mommy, why don't you pick up my toys and I will play with my trains! That sounds like a good deal!

LOL. If I can't win a negotiation with my toddler how am I ever going to close deals on the job!!!