Read the passage given below and answer the question.

You seemed at first to take no notice of your school-fellows, or rather to set yourself against them because they were strangers they knew as little of you as you did of them; so that this would have been the reason for their keeping aloof from you which you would have felt as a hardship. Learn never to conceive a prejudice against others because you know nothing of them. It is bad reasoning and makes enemies of half the world. Do not think ill of them till they behave ill to you; and then strive to avoid the faults which you see in them. This will disarm their hostility sooner than pique or resentment or complaint. I thought you were disposed to criticize the dress of some of the boys as not so good as your own. Never despise any one for anything that he cannot help least of all, for his poverty. I would wish you to keep up appearances yourself as a defence against the idle sneers of the world, but I would not have you value yourself upon them. I hope you will neither be the dupe nor victim of vulgar prejudices. Instead of saying above "Never despise anyone for anything that he cannot help," I might have said, "Never despise anyone at all"; for contempt implies a triumph over and pleasure in the ill of another. It means that you are glad and congratulate yourself on their failings or misfortunes.

'Neither be the dupe nor victim' can be best understood as :

Neither be the fool nor the sufferer

The phrase "Neither be the dupe nor victim" can be best understood as Neither be the fool nor the sufferer.

A dupe is someone who is easily deceived or cheated, while a victim is someone who is harmed or injured by someone or something. In the context of the passage, the author is warning the reader to be careful not to be easily taken advantage of or harmed by others.

The other options are not as accurate or relevant to the meaning of the phrase. A guide is someone who provides information or assistance to others, while a user is someone who takes advantage of or exploits others. A slaver is someone who sells or trades slaves, while a slave is someone who is owned and forced to work by others. A target is someone who is aimed at or intended to be attacked or harmed, while a shooter is someone who uses a gun or other weapon to fire at a target.

Therefore, the most accurate and relevant interpretation of the phrase is Neither be the fool nor the sufferer.