2 sentences for 吃亏 (chī​kuī — suffer loss)

1. 他宁可自己吃亏，也不愿让朋友受损失。

   tā nìng​kě zì​jǐ chī​kuī, yě bù yuàn ràng péng​you shòu sǔn​shī.

   He would rather suffer a loss himself than let his friend suffer one.

   Source: Dong Chinese Dictionary

2. 要是不懂其中的门槛，买东西很容易吃亏。

   yào​shi bù dǒng qí​zhōng de mén​kǎn, mǎi dōng​xi hěn róng​yì chī​kuī.

   If you don't know the ropes, it's easy to get ripped off when buying things.

   Source: Dong Chinese Dictionary