i went investigating them on the weekend, i talked to a guy at jb hifi who told me some obvious stuff you wouldn't think of eg:
if its got a 60 meter range and you go past it the thing doesn't stop but you no longer have control !! he told me how his father watched his drones first flight over the beach end up in it going out to sea and keep going before running out of battery and dropping wayyyyyyyyy of shore into the ocean !!! $300, 1 flight, sunk !!!
also when they run out of battery, they drop, so if its up 20 meters its not going to survive !!
you pay for what you get, cheap ones have cameras but no wifi so you don't know what your filming, a little more money hooks into your wifi/android/iphone but you still get the "dead into the ocean" problem, a little more money and you get gps so it forces it to stay in range, a little more money and now you are in for @ $900 + you get "return to base" so it will come back in time before battery runs out.
so for me i would go for anything less then the $900 which means i at least get more then 1 go with it not like a $300 ocean drop.
so unfortunately that puts it outside the 9yr old birthday present, thankfully i didn't tell him i was even considering it, so no harm done.
tim