Aoshima Grand Champion 9
Price is per car.
Aoshima Grand Champion 9 (Aoshima Granchan Series 9) includes six car models with two colour variants (so, that's 12 in total) + apparently a "secret" car.
They are randomly packed into small boxes that resembled those small cereal boxes you took on holiday, then randomly packed into larger boxes of 12.
Since the boxes are sealed and identical, there's no way of me knowing which is which, so you will probably get duplicates.
There's some good write ups of Aoshima on the Lamley blog - definitely worth a read.