YOU SAID:

nobody wants to buy sea shells if they could just go to the beach and pick one themselves.

INTO JAPANESE

貝殻をビーチに行って自分で選ぶことができれば、誰も貝殻を買いたがりません。

BACK INTO ENGLISH

If you can go to the beach and choose your own shells, no one wants to buy them.

INTO JAPANESE

あなたがビーチに行ってあなた自身の貝殻を選ぶことができれば、誰もそれらを買いたがりません。

BACK INTO ENGLISH

If you can go to the beach and choose your own shells, no one wants to buy them.