You said you didn't understand my question
Are you asking if we treat a girl we fuck for money differently to a girl we fuck for favours and gifts?
Clearly your answer to the question is "yes", you treat WGs differently from GFs. That is somewhat ironic, since you acknowledge your GFs EXPECT you to pay their way as well as yours. Would they still sleep with you if you stopped buying things or insisted on 'going Dutch'? Not reading too much into that - maybe you're rich and you choose poor GFs - it's just interesting that you draw a distinction between a cash transaction and a goods transaction.
But none of that matters ...
The whole point is that oscarmandude's question was precisely about crossing that separation - a separation you perceive and act on, and one that his mate has chosen to cross over. It's not about treating them differently, it's about what happens when a customer chooses to become a BF.
If oscarmandude wants to support his friend, the first thing he needs to do is become clear on HIS OWN values and preconceptions, before he can take action that has a chance of supporting his mate.
MY opinion of WGs, GFs, and how to treat them is neither here nor there, and your pity for me is a huge leap of projection.