So I'll ask the question again, why, if they're not prepared to pay for the membership, should they jump the queue for those that do.
I even put the word in bold to highlight the joke.
In answer to your question though, we don't all worship at the temple of Mammon. Sometimes people would like their mate or a relative to have the ticket for free rather than flog it to some random. The other people in the group would probably prefer it to go to someone they know too. Aside from that, sticking on the exchange doesn't even guarantee a sale.