Usually the choice of friends depends much on compatiability, what concerns their social background, their educational standard as well as their financial ability. So in most cases they will have similar pockets,in other cases some people's friendships are built on much deeper levels of connection,which is rare.In those cases, financial disparity won't stop their friendship from flourishing. However in most cases it could be a reason for them not to start a friendship from the very beginning.

Ideally, true friendship is not based on money. Friendship should be an in-depth relationship combining trust, support, communication, loyalty. However if your friends have more money to spend than you have, you may not be able to go to the same places they can afford to go to and that may signal the end of a friendship.