Buying a frost free fridge freezer?

Hi I would like to buy a frost free fridge freezer and have seen a Beko for �259 in Comet. i went into a local dealers shop to look at theirs, and he showed me one at �440 and said I should buy from him and not Comet or Argos as they were liable to break down. He also said Beko was a budget make, I haven't much money, and I hate defrosting my old banger once a month. Please can you recommend a frost free fridge freezer which is a good make and which will last as I am really confused? Thank you.