Bottom line - shop around. Ask what is the TOTAL cost of the course INCLUDING the course fee, instruction, equipment rental, dive boat, ferry to Catalina, certification card, and what equipment will be required to purchase. This will let you compare cost apples to apples. Cost is not the most important factor (yes, I know it matters), but value quality of instruction over quick and cheap. Talk to the instructor etc.
In todays market most SCUBA students want it fast and inexpensive. They don't want to pay an instructor for longer classroom instruction or pool time. Many would like to get certified in one weekend if they could. If dive shop X is charging $ for a 4 day course, Dive shop Y can't very well charge $$ for a 6 day course and get enough students to stay open.
1. When I got certified I was quoted a price that was reasonable. Then I learned the price is only for the course instruction. It does not include the books, e-learning, file folder, dive boat/ferry, pic folder, certification card or required equipment. So my out of pocket ended up costing about 3 times more than the original amount (that was just the course fee). Again, Price is not the primary factor to consider. The price alone does not dictate if the instruction is good or bad. It is the instructor.
2. Training, a few hours one week night to process enrolment, waivers, and get our rental gear. Then two weekends (one for classroom and pool and the other for open water dives) and we were done. Certified?.... Yes. Trained....well sort of. We knew what to do.... Competent in our scuba skills, Far from it. Find an instructor who values quality of instruction and learning over speed.
3. A large chain does not necessarily mean quality instruction or bad instruction. It just means they sell all kinds of sporting goods and have other sources of income besides SCUBA. There are great instructors in small shops and some good independent instructors who don't work out of dive shops at all. Shop around, get comfortable that your instructor knows what they are doing and values your learning and learning it well over speed.