One day, I saw a beautiful piece of eel just sitting there, unpriced, and I asked the fisherman for it.

有一天，我看到一条很漂亮的鳗鱼就摆在那儿，没有标价，我就向渔夫要了它。

Although mostly unpriced, it is the most valuable stuff in the world.

淡水虽然没有标价，但却是世界上最珍贵的东西。

Finally there are external effects: the unpriced costs reflected in the modern environmental crisis.

最后是由外部效应：未标价的成本反映在现代环境危机中。

So one day I saw a beautiful piece of eel just sitting there, unpriced, and I asked the fisherman for it.

所以有一天我看到一条非常好的鳗鱼放在那里没标价格，我就会向渔民要这个。

Perhaps, then, slower population growth would reduce the pressure on fragile environments and conserve unpriced resources?

那么，或许减缓人口增速可以减对轻脆弱环境造成的压力，保护无法估价的资源？