我们通常用 very cheap 来表示非常便宜，还可以用一个意想不到的习语 for a song，它的起源可能跟街头歌手有关，寓意：
1、incredibly inexpensive 非常便宜
2、to get something for a surprisingly low price 以惊人的低价买到东西
3、to buy something for less than it is worth 以低于其价值的价格买东西
4、reasonably priced 价格合理
5、low-priced 低价的，廉价的
例如：
1、She bought a pair of lovely shoes at a flea market for a song.
在跳蚤市场，她买了一双可爱且非常便宜的鞋子。
2、We bought our house for a song.
我们非常便宜地置办了我们的房子。
3、Portable speakers of Bose are going for a song on last day of the sale.
在销售的最后一天，Bose的便携式扬声器正在进行大促销。
4、The clothes of my favorite brand are going for a song in the neighborhood shop.
在附近的商店，我最喜欢的牌子的衣服正低价出售。
5、Who rumored that the tickets of Justin Bieber's concert in New Zealand will go for a song.
据说贾斯汀·比伯在新西兰演唱会的门票将以非常便宜的价格出售。
6、I have never seen such a sale before, things here are going for a song.
我以前从来没见过这样的大甩卖，这里的东西正在进行大促销。
7、These watches are very expensive in Canada but you can buy them for a song in Switzerland.
这些手表在加拿大很贵，但在瑞士你可以非常便宜地买到。
8、Amazon is a great place to shop online, sometime they sell goods for a song.
亚马逊是一个网上购物的好地方，有时他们会以很低的价格出售商品。
解析：sometime 作为副词的时候，表示某一个不太确切、没法确定的某个时间，既可以指过去也可以指将来。