Islamic Interpretation of Dreams (Ibn-i Sirin):

(Attire; Goodwill; Secondhand) Buying used clothing in a dream means poverty, but selling worn garments in a dream means good deeds, for in that case, one repels his aggravation or unwarranted adversities.

A thrift shop salesperson in a dream represents a layman.

Selling used clothing in a dream also means putting an end to one’s problems.