The only reason why dive shops do dive training is because they anticipate getting some profits from equipment sales. To sign up for lessons that they lose money on, then turn around and buy mail order dive gear is just totally and completely uncool and dishonest. The LDS is going to bail you out time and time again with emergency repairs, loaners if needed, dive trips, advice up the wazoo.......give these guys a break, it is not like they are driving Mercedes and BMW's off the meager profits.
If I were absolutely hellbent on doing that, I would be straight upfront with the LDS and tell them first, then ask them to charge me a revised price where they make a profit off the lessons. Or better yet, tell them you HAVE to have DiveRite gear, and you would rather not buy it mail order, ask them if you can buy DiveRite through them......give them a chance, they will work with you.
I can waltz into my LDS, grab their tools and work on my CCR, shoot the breeze, volunteer to pitch in for their SCUBA introductory barbecue days, Ive sent gear back that although i rodered that size, they swapped it for different sizes, I've returned special order expensive video monitors for full credit applied towards HiDef external video monitors that will be available half a year later, I've loaned them my gear for shows, etc, all because we built a relationship, it totally pays off......I even had my employees repipe the home of the owner of my LDS and traded it for dive equipment. You can't do ANY of that with a mail order house.