By the way, with a tiered system, most people would go to 1'rst tier places first, for mainstream budget diving with short travel times.
Then, over time, as they get more seasoned, capable of handing a wider array of conditions (e.g.: currents in Komodo), get bored with 'same old reef' diving & want more exotic encounters (e.g.: mantas in Hawaii, tiger sharks at Tiger Beach, great whites off Guadalupe) or more lush reefs (e.g.: Fiji, Indonesia), and maybe get a little older with more disposable income (or just more scuba focused & willing to sacrifice other things to pursue it), they get willing & able to take 2 or 3 weeks vacation & spend 2 or 3 times the amount to go somewhere extra special.
Now, me, I'm a 'Wal-mart Diver.' I've been to Bonaire 7 times, did a 2 tank dive in Cozumel, also in Grand Cayman, also in Puerto Rico & Costa Maya and 2 of them in St. Thomas (the 2 tank trips on cruise vacations). To me, $2,500 per person total trip cost for a 1 week trip is the rough ceiling on the travel budget, and I like tropical aquarium conditions. So to me, cold water with currents in the Galapagos, or $12 grand to hit PNG and a lot of travel time, is not going to happen.
But just like with food, wine, art & other things, we have people who've 'done Wal-mart' so to speak, and have the time, means and discriminating palate to make those upscale trips worthwhile.
I look at their pictures sometimes.
Richard.