Nothing is inexpensive in Pacific especially considering airfare and jetlag (especially from East Coast) unless you can afford two-three week long trips (kinda beats the inexpensive part, doesn't it?).
I'd consider Caribbean for a while (Belize, Roatan, even Puerto Rico) until your youngsters get comfortable enough to consider LoB.
@FreqFlier
I respect your opinion, but I disagree with the statement. I'm fully aware that being situated on the West Coast gives me a bit of an advantage going west, however if it's a well connected route (like NYC -Tokyo) as a first leg, the difference is only ~3 hours.
My point is mainly that diving in the Pacific (and the Coral Triangle) is significantly better than virtually anything in the Caribbean because of the delta in biodiversity (more flora and fauna), fewer divers, and in many cases, more authentic cultural experiences.
Just a small example to illustrate the point:
~65 species of hard coral in the Caribbean
~ 450 species of hard coral in the Pacific
(It is estimated that the Coral Triangle contains over 600 species of hard coral and soft coral)
This extends to fish life as well:
~ 1,700 species of fish estimated in the Caribbean
~ tens of thousands of species of fish estimated in the Pacific
Note: not all of these can be found at diveable depths, however the ratios generally hold true.
The Caribbean is beautiful, however it's like a pond. Very little diversity (relatively), overdived, and culturally not that interesting.
Getting to the Pacific, exploring different locations, etc. does take more travel time, however it's worth it.
My wife and I started in the Caribbean ~20+ years ago. We've only gone west for the last 15+ years (except for a couple of trips to the Red Sea). Still more places to dive...