The Cowboy
Player Valuation: £60m
It is if you get a disputed delivery - "I didn't order it, my kid pressed the button." Just not sure how a push of a button can be classed as acceptance of a contract unless it's reasonable that only an authorised person can press the button.
All that said, Amazon refunds easily anyway, but it's still a point to consider. All in all a great idea though for certain people.
Pretty low cost items, plus if they're meant to be for regular repeat orders then it's not the end of the world if your kid presses it. Probably has an override if it's pressed repeatedly in succession.