mean people who always have enough money to buy themselves things but never enough to contribute to 'the group'

example a - at a pub with friends

chris - "hi person a, how are you?"
person a - "im ok - i just bought some new shoes for a hundred pounds"
chris - "they are nice - do you fancy a drink?"
person a - "yes, why not"

chris gets drinks - chris and person a drink drinks

chris - "yum, those drinks were nice. fancy another? your round?"
person a - "i don't have any money, i spent all mine on my shoes"
chris - ":O"