One of the most common excuses people give for not pursuing diving is the cost. It certainly isn't as cheap as renting a movie, but compared to other outdoor or sports hobbies, it is relatively inexpensive.
I live in Alaska. Outdoor sports range from snow machining and hockey to 4-wheeling and hunting. SCUBA can be the LEAST expensive of all of these endeavors. The cost of a snow machine or 4-wheeler alone exceeds the cost of all of your SCUBA gear and training through Divemaster, and maintaining these machines is far more expensive than an annual service on SCUBA equipment. The useful life of any of these motorized death-traps is far less than properly maintained SCUBA gear. There simply is no comparison in cost. Hockey is a sport usually entered early in life and pursued through mid-life if one is avid. The sport takes a toll on the body and requires equipment equal to the cost of SCUBA gear. Hockey is also typically played in the winter months and is not typically done year round or not at all in some locations one might move to. SCUBA, on the other hand is done in most all communities, as there is always an ocean, lake, or quarry nearby. Diving is also a sport that is done from very young to very old, extending participation in your hobby years longer than others.
And for shooting sports, firearms and their accessories certainly add up. A quality Colt h-bar or Rock River AR with a red dot sight, a couple of magazines and an after market trigger is more expensive than buying all new SCUBA equipment.
All this banter is fine and good, but what does it cost to dive? An Open Water Diver certification from the most widely known and accepted SCUBA training organization in the world runs about $600-$700 in most locations. This certification is good for life and is recognized world-wide. Try flashing your concealed carry card for your pistol in Canada and see where that gets you! Additional training ranges in cost but all the training required from zero to Master SCUBA Diver (the highest non-professional rating) is going to be roughly $2,000. This training can be obtained over the years or can be completed in a number of months.
Gear is another cost to diving and is essential. One might consider renting gear used only on occasion, however, having one's own gear is less expensive in the long-run than renting if you dive frequently. You should try to own your own Buoyancy Compensating Device, regulator set, mask, fins, snorkel and wetsuit, as well as a dive computer. If you buy good, used equipment (for example: the gear you received your training in), the cost for all of this gear can be from $800 to $1,200, depending on age, brand and features. Christmas and birthdays are for upgrades and your dive gear wish list. Following this initial investment, buying air fills in rented tanks runs from $10 to $15 per cylinder for air and up to $17 per fill for enriched air Nitrox. So you see, diving gets less than the cost of a movie after the initial investment.
Diving can be enjoyed for the rest of your life and anywhere around the globe after a relatively small investment. That cannot be said for most other sports or hobbies; and no other can let you see the other 70% of the earths surface and the life that inhabits it. Diving, it turns out, is actually a bargain!