Second-hand shopping: establish who the seller is first
Professional sales and purchases from private individuals have different protection frameworks.

Second-hand shopping gives clothes and objects another life. First establish whether the seller is a professional or a private individual.
Different rules
Your Europe explains that used goods sold professionally have legal-guarantee protection. Some countries allow a shorter agreed period, but never under one year. The corresponding EU rules do not cover purchases from private individuals.
Request accurate wear descriptions, photographs and proof of the transaction. On platforms, read their own terms too. A low price is less useful without clear information on condition and how disagreements will be handled.
English translation of the Greek edition · Read in Greek