Watch the areas where you get Personal Training

I am looking for a personal trainer. The only way to do this is to book online. When booking online, I noticed the price varies between areas. The "richer" the area, the more expensive the sessions. I don't understand this, I don't have a lot of money but work in what is seen as a "rich" area. Are the sessions different here? Why am I paying more for the same thing?? Makes no sense to me and I can't afford this so really Virgin Active, how are you helping people with their health, really?