I got certified a couple of years ago and really enjoy scuba diving.
Course costs vary from place to place. You generally get what you pay for. You could get certified for a couple hundred bucks just for the course and rental equipment. If you got a real top end class that even included a couple of real dives it would cost more.
You can spend hundreds on owning your own equipment, but you can rent to start with to save money.
I would ask around and find out what people in your area have done and how happy they were with their experience.
i have been diving for about nine years. it was $120 CDN then, who knows how much now? what i say is GO FOR IT!!! if you have a salt tank you'll never regret diving reef after reef after reef... to see all the fish and beautiful animals nature has to offer. besides, this hobby although expensive is the closest thing to floating in space i'll ever get to experience!
Call your local dive shop and ask about their open water courses. Most will want you to buy your own mask, snorkel, fins, gloves and booties (if you need them in your area), but will supply the rest as part of the course. PADI and NAUI are known all over the world. SSI is moving up, but still unknown in some places.
I am off to the BVI in a week for some diving. Should be alot of fun. A better forum for scuba related questions would be www.scubaboard.com They are a great bunch of people over there as well.
I love diving, really makes you appreciate this hobby. The initial gear is expensive, but once you have all your gear it can be affordable. I get a season pass to the local "lake" and dive all summer for only the cost of fills. $5 a tank, 2 tanks a day its only $10. Of course going to more exotic places will set you back.
And of course you also get to witness the destruction on the reef. I have been snorkling/diving this reef all my life and have seen many ups and downs but this kind of stuff always angers me.
Ah, the BVI. Ive been there, snorkeling but its still beautiful. Check out Normans island/cave thing, its great also the shipwreck is cool. There are thousands of longspined urchins, so take care! 8)
Righty pretty much has it summed up. Don't forget the potential costs of your open water portion of the class. Depening on where you live there's admission fees or if you are on the coast, the cost of a boat trip, unless shore access is avail. I was working a college job when I got started and my shop had nice used gear. I bought my first reg. set-up that way and saved quite a bit. I still use it to this day and it works perfectly with regular maint. of course.
One other cost...once you finish the open water course, I almost guarantee you'll want to get certified in other aspects like advanced, caves, deep, photography, etc. Like aquaria, it's a potentially expensive addiction, but worth every cent.