I don't think that the one I've got is mega expensive, but it's masses of fun.
The biggest downside is that it's not meant to be used outside unless it's
really calm out there. That means you need a fairly large/clutter free space to be able to fly it indoors.
It's seriously good fun though. Even if all you do is run he rotors up to just about take-off speed and enjoy the down-draft that it creates
I'm loving mine, but I certainly wouldn't say it's a toy - and I get the feeling it's not going to be a cheap hobby either. I think the repair bill I've racked up the last couple of days just learning to hover will probably come to about £40.