I'm getting my OW cert through a LDS. Items that the LDS has reasonable prices on (generally smaller accessories) I purchase through them.
But let's face it, it's impossible for me to pay $500 for a regulator that I can get from LP for $250. As for service, what service? The things I have considering purchasing from LDS's do NOT have any advantage vs. purchase online.
If the LDS offered a few years of free annual maintenance on say a regulator, I'd certainly consider paying more and purchasing locally. But they don't. LP matches the manufacture Warranty, and in most cases that covers manufacture defects. However it does not in most cases cover stuff like wear and tear on BC's, orings annual maintenance or EVEN inspection.
My LDS will get my business on maintenance, and if they are NOT VERY glad to get that business which I will pay for, and have a good attitude supporting equipment that I did not purchase through them, then I will find someone who is.
The LDS I'm using is hardly small. They have a very large facility, about two dozen instructors from the Maser level to AI's, a travel agency, a pool, classrooms with Plasma TV's, full shower and kitchen facilities, air and nitrox fill stations, a rental section, the works! Unfortunately their prices stink compared to even places like Scubatoys who is ALSO a LDS.
IMO if they wanted to compete on prices by increasing volume and selling online, they certainly appear to have the resources. I think they have chose NOT to do so, and would rather make ONE sale with a 100% markup, vs. having to make three sales to get the same margin. That is certainly their choice, and my choice is to find better prices.
Ron