The bottom line, in my opinion, is you may be taking your own life in your hands by looking for the cheapest path. YOU have to consider whether or not you are getting the training necessary to stay alive and healthy! Then again, I would not buy the cheapest equipment either. But that is just me...
I have to respectfully disgree with this concept. I have a pal that runs a dive shop in a very wealthy upscale Florida town. He calls it a BMW-Mercedes community. That shop has to be in a location with the aura of dive boutique. Folks there won't step into a place unless it looks really nice. A high rent location means passing on the costs to customers through higher prices on gear and training. Folks in that town won't blink at the extra cost.
The other guy I like (see link) is in a little ranch house on a sidestreet and used to operate out of his own home. He is really low overhead.
Both will do a good job teaching, but you will pay according to the location.