How can blackberries be this expensive when they grow wild along my uncle's fence?

How to say “How can blackberries be this expensive when they grow wild along my uncle's fence?” in Japanese

In Japanese

おじさんちの垣根(かきね)に勝手(かって)に生(は)えてるのに、なんでブラックベリーってこんなに高(たか)いの？

Ojisan-chi no kakine ni katte ni haeteru no ni, nande burakkuberī tte konna ni takai no?

How can blackberries be this expensive when they grow wild along my uncle's fence? in other languages