In any family all siblings are never in the same league financially and whenever there is a celebration, there may be a rivalry in unimportant things like jewellery or clothes,I always wore whatever I could afford and felt confidant too, and everybody loved me for that and for what was me.....I was still very popular.
I remember one of my friend's kids used to study in DPS and there children would bring expensive gifts for classmates on Bdays and her children would crib and say that if they cant give the same, then they must be poor..see the children's perception...But my belief was.make friends with only those who value you for you not for the gifts, I fixed an amount for bday gifts and my daughter gave the same to all her friends irrespective of whatevr they gave her. They were studying in a private school and she was friendly with a cricketer's daughter too...so what..let her do what she can, you do what you can..show your worth thru other things...study well, take part in extra activities, be a good human being....In spite of all this pressure my children made many friends and good ones and they were quite popular.My daughter used to help her classmates in studies and run a comics library too when she was very young..must be in 5 or 6 class..
Many people believe that if all the group has AC, car(or any such thing) in the home, my child should also have, otherwise he/she would get a complex..NO..complex comes because we dont tell them what is important in life, we dont share with them our economic compulsions..And our values are shown by our behaviour , not by lecture.
I have come up the hard way in life, so i can give you hundred of experiences where I could change my values due to peer pressure, but I never did, I tried to focus on my strengths..like my knowledge, my reading, my social skills( yes I have been managing many social gatherings like library, parties, club etc...).
So I would say try to grow as an individual and you are sure to find some people who will like you for what you are and they will be your true friends