4 sentences

1. 我有一封卖家的信。

   wǒ yǒu yī fēng mài​jiā de xìn.

   I have a letter from the seller.

   Source: OpenSubtitles

2. 这位卖家的信誉评价很高。

   zhè wèi mài​jiā de xìn​yù píng​jià hěn gāo.

   This seller has a very high reputation rating.

   Source: Dong Chinese Dictionary

3. 卖家给这件古董开价十万元。

   mài​jiā gěi zhè jiàn gǔ​dǒng kāi​jià shí​wàn yuán.

   The seller is asking 100,000 yuan for this antique.

   Source: Dong Chinese Dictionary

4. 卖家承诺在二十四小时内发货。

   mài​jiā chéng​nuò zài èr​shí​sì xiǎo​shí nèi fā​huò.

   The seller promises to ship the goods within twenty-four hours.

   Source: Dong Chinese Dictionary