vendor mounts ARE goldsinks. their sole reason of being is to make people waste gold and take that gold from the economy. that's the very definition of a goldsink.
sure, the average joe doesn't buy them because they are too expensive. but the average joe doesn't need a gold sink, because he doesn't have gold overflowing from his pockets.
I am an average joe I can never make more than 30k, EVER. I don't need a gold sink, I need better professions lol