If this is a daycare child then you need to speak with the parents because that is likely where he learned his negotiating skills. The parents need to be educated as to what effect their behaviour is having on the child and how they need to be the adults and set limits for their child. Doing whatever it takes to get cooperation is not parenting.

With really cheeky kids sometimes a similar treatment back works. Just tell him plain and simple your house your rules. When he is an adult with his own house he can make his own rules. While he is a kid he will follow the rules of the adults around him. At least you know by the abc statement what he is hoping to get which of course he should not be given. That should give you some idea of what is important to him and something you can use. There is a fine line between being nasty and being firm and this is the type of child that is wise beyond his years so to a certain extent you would use the same tone of voice and hands on hips body langauge you might use with an insolent teen. Here me response when he said the ...do abc phrase he would be told "I don't think so. My house my rules. You will stop xyz because that is how we behave in this house." Do not mention his abc request at all as if you didn't hear it. Deal only with the xyz. He is in a sense negotiating but also trying to throw you off the original infraction.

There is something to be said for sticking with toddlers that don't talk. Whining and crying is easier to tune out than insolent older ones.

If this is your own child well wish you luck, lol.