We are the 'consumer' so we can influence prices by not visiting. Simple as that. But, we are blokes and we think with our knobs.
Experience (20 years punting and in several countries) suggests that in average this is unfortunately far from true.
I've seen a number of English girls who blamed EE for pushing the prices down. This -admitting it was true- was almost merely short lived: English girls didn't simply disappear from the market, they've put their prices up.
The issue is a bit more complex than that in truth. Local girls only want to maximise their profits. For them, paying £3K in renting for a flat somewhere in London is not worth it, then here it goes someone who would hire it for the high end market and charge an absolute arm and a leg for foreign WG (south americans, invariably).
So long as there is a "market" prices will only go up.