Where to buy?
Surely not in a supermarket or in general toy shops. Why? Because it's the lottery. It is impossible for you to have reliable customer feedback on the quality of the material. Drones are unknown brand. Sold in promotion a fortnight, they will disappear completely from the landscape. Unable to find spare parts. At the first crash, the first breakdown, it's game over. Direct to the trash.
There are loads of Chinese merchants selling these devices at unbeatable prices. Is it worth it? Yes. Are their devices reliable? Not all of them, but there are some very good ones. Is there a follow-up, a technical service, a service? Yes, but it is better to know English. The few times I had problems with a device, this one was quickly refunded, after a few emails (in English).
There is no scam, trap, fraud. Since the time I buy in China, I have never had to pay surtax, but some have experienced this problem. Personally, I buy a lot with Banggood, a site that is very supplied in drones, quadricopters of all kinds, and in spare parts. I also bought Wish (less competitive at the price level) and Amazon. The weak point of the Chinese sites is the delivery time. Count 3 weeks-1 month. If you're in a hurry, check out Amazon, or FNAC. It will be more expensive, but you will soon be delivered.
Some known and reliable sites: Aliexpress, Bangood, Wish, hobbygaga, hobbyking. It is better to use a Paypal account for your
purchases: it is safer and you will not be penalized by your bank (fees outside Euros, it depends on banks).
Do not hesitate to compare and compete. Some specials can be unbeatable.
And if you subsequently get bitten, you want to go up the line and buy more drones, racers, do not forget the French sites. Their plus: a direct contact with the customer. These passionate people are pros of the drone and will advise you.
But before you buy, you have to answer the question: