If yours is real, then it is rare and worth the money. It was released for the GBC when the GBA had already been released.
That's probably why they didn't make very many, and thus why it's rare.
The Chinese listings you are referencing are definitely fakes.
The original cartridge is see-through, not red.
Whenever there's a Chinese seller with a stock photo selling multiple copies of a game, it's most likely selling fake copies. Especially if they're selling games that are supposed to be rare.
A lot of the time people are aware of this though, and just buy them because they like to have physical copies without dishing out exorbitant amounts of cash.