Ok, take it easy on the locals.....
Remember, if you don't like it, leave it.
Now, as for buying dive gear. If you are an instructor then many businesses offer great prices. I would not bother shipping anything that will not fit in a balikbayan box. Most places have a shipping company that specializes in shipping balikbayan boxes from anywhere in the world to the Philippines. I have used the service myself over 50 times in the last 6 years. The boxes are pretty big (36" X 36" X 36" square). I have shipped tanks before. You can put 9 tanks (w/padding) in one box. Check with your local Pinoy population about who they use for shipping. WELCOME TO THE PHILIPPINES! MABUHAY!!