It is a great question. Thanks for asking it, and thanks to others for their contributions/insights.
I have 4 children, one of which should be off to college next year, so not too much dicretionary income to spend on diving at the moment. I've found that it's not so much the cost of diving... it's the entry cost to the sport that can be off-putting for the budget minded. Like many people here, I'm jusdcious about buying equipment (buy good quality, but buy it used and have it serviced), and I mainly shore dive & occasional boat dive locally around New England to keep costs realistic. I also got one of my sons interested in becoming a junior Open Water diver... so that now doubles my costs! (and also doubles my fun!). Now my daughter is showing interest (do I qualify for one of those government bail-outs yet?)
My real question/contribution ot the group is this: Since, it seems, the vast majority of us dive locally and, perhaps take an occasional exotic trip (that would be a vacation for 6 of us in my case!- Eeek!), WHY are the dive magazines made up of 90% "reviews" (read: "Marketing") of exotic places? It drives me nuts. Is there a really good magazine out there with great content, good, technical reading aimed at improving tenchniques and broadening a diver's horizons without wading through page after page of photos of places I will not be able to afford to go to until my last child exits college and I'm probably ready to retire?! My wife loves looking at the pictures... but for me, I lost interest & cancelled my subscription.