To be blunt, the physics don't change for the age of the flier. A sail on a boat is still gonna push the boat no matter who controls the lines. It's the type if kite you fly that makes the difference
If you're looking for a bare bones entry level sport kite, SkyDog kites has some low cost kites. Also, you can get a Prism 1.2 foil made for zooming fun, that has very little pull , but is almost impossible to break. An entry level dual line sport kite isn't going to do any tricks....easily.
There are plenty of single line kites (SLK) that are cheap, but good (Premier Kites, HQ kites, Prism, etc.), but I don't think that would hold their attention for long.