Woah. I was expecting them be a tad more professional...
So if you want to buy:
150$ you get 1 BTC ~ 52083.33 USD , while right now the price is $ 47563.
There was a topic not long ago comparing OTC services with actual exchanges and the result was clear: this kind of service is OK only for small amounts of money, since exchanges have quite expensive withdrawal fees. I guess that various services have various fees and requirements too. Clearly it's not cheap. OP mentioned ATM and those aren't cheap either. Having them hidden in the exchange rate, on one hand, can at least mean that they're all in one place and it's easier to calculate (the loss/premium caused by the fees).