Word/phrase for over asking as a tactic to get what you really want
Anchoring high
If websites on negotiation are to be believed that kid has professional negotiating instincts.
Anchor first and anchor high and you'll be playing in the big leagues is an article on the psychology of negotiation. The anchor is the first sum on the table and the article, unsurprisingly, suggests the negotiating party ask for a higher sum than they would be prepared to take. Harvard Law School gives some advice on how to overcome the anchoring bias.