Having been in the hobby in NYC and through the world for over a quarter of a century, I have seen changes up and down (forgive the pun), based upon economic boom and bust, and changes in political sensitivities. The circumstances vary depending upon the local, but what follows is my view of the history of the Hobby in NYC. When I started, it was escorts through agencies, varying in price and quality. Al Goldstein's Screw magazine was the major source of information. Before my involvement (the 1970s), there where very high end massage parlors, often with Roman theme, that represented the locus of action. Then we had a number of review magazines such as Action(this is NYC in the 80s and 90s) that would serve to direct the hobbyist to houses, brothels essentially, where one would have a choice of ladies; as I recall the prices were quite reasonable, and I met many nice ladies, although the ambience would vary from luxurious, to utilatarian, to downright squalor. I think the rise in real estate prices led to the virtual demise of the brothal in NY by the late 1990s.
With the economic boom, we saw the rise of the high end escort, the $2000 an hour and up variety, which priced everyone but the Wall Street traders out of the market (I took a breather myself during that era). Of course, that ended abruptly, and now we enter the era of the independent provider, which due in part to boards like this, and the ability on the internet for providers to share information, and hobbiest to likewise share, leads to a relatively happy median, and probably a much less exploitive and much more congenial environment for both provider and hobbyist. I am sure that with either a change in the economy or a change in the political wind, we will see a new variation, for good or for bad.