Look around there a lot of good shops with different focus and they all have a target market.
I agree. It would be helpful if the OP indicated if there were a specific need or quality they were looking for.
Some will charge a lot for equipment maintenance but when the job is done you know it was done well by a professional and it is unlikely to fail on you somewhere where you can't get it fixed.
I hope you are not implying that high fees equals good service. I have NOT found any correlation to that in diving, or any other product/service I have been involved in procuring over the last 35+ years in that business.
While it is true you must pay a fair price for the work performed, paying more almost NEVER yields a better job. Do you think you will get a better Big Mac if you pay more for it? Better gas at the filling station simply because you pay more for it? I seriously doubt it. I can submit that if you pay way under the fair price, you will likely get poorer quality, but can't guarantee that. A lot goes into (or should go into) pricing goods and services. Much of that is not apparent to the consumer. I've procured great quality goods and services for way under market value, just so the company could stay in business until better times came around. I must admit that I never knowingly procured the most expensive goods or service. I don't believe in "gold plating".
That said, I learned my expensive lesson - the destruction of a regulator - the hard way. I now either perform my own work, or find a shop that will do a good job in the specific work I'm looking for. It would be nice if a single shop had the corner on all the scuba goods and services, but I don't know of one who does - at least in Colorado. But a show who has good customer service and really cares about the customer is much more likely to fix a problem when it come up, than one who doesn't.
Instruction varies all over the place. I have seen good and average instructors in about every shop I have ever dealt with.
I am a non-practicing Dive Professional. I have worked with and witnessed excellent to below average instructors in Colorado and the Caribbean . I do agree most fall in the good to average range.
I travel a long way to Flatirons in Broomfield because of their technical training. They are are good sized shop who really seem to know who their customers are and care about them.
I too travel a long way to Boulder (from Colorado Springs) for my technical training. I'm told that Ocean First Divers (OFD) is the only shop that has DIR-type post fundamentals training. I could be wrong. They also have the best stocked showroom I've seen, especially for post recreational equipment, in Colorado. I openly admit I have not visited all the shops in Denver area though. I think this point further supports the need to know what goods and services one is looking for - since it is doubtful that a single shop will be the best at everything.
As far as costs go I try to buy with whatever shop I train with. If you really want the best deal you are going to buy off of the internet but when I do that I always feel guilty since I know the local shop needs a higher price and these guys aren't making a killing off of the business.
I do an awful lot of shopping off the internet. Sometimes it is because of a good deal or sale (I got a lot on Black Friday Sales) but just as important is that I can get it just as fast, in many cases. Many shops don't carry tech gear. And those that do are 200-300 miles (round trip) away. So, if I'm in the area, and they have it in stock, I'll buy it. But, they often have to order it, and I can't see driving 400-600 miles to buy something I can have delivered to my house sooner and cheaper.
I recognize that dive training is not a money maker for the dive shops, and selling equipment to trainees is a major source of income. I try to direct potential buyers to dive shops when they aren't sure what they want. There is nothing like a well stocked dive shop to try on various masks to see which fits the best. Some even let you try them on in the pool. That's pretty hard to do with a large internet distribution reseller.