They weren't computerized before or didn't bother to do a conversion from their previous inventory management software? That's a pain in the butt for sure, but I can't imagine running any business without having computerized inventory. It would be a mess. If you had to re-inventory everything, it would probably be a good time to get some barcode or rfid stickers and a reader.
Sure, they have it computerized. But, that doesn't mean they have the expertise to extract the data from the existing system that is used for the brick-and-mortar (which may be proprietary) and then import it into whatever online, Cloud-based store's database they are using for that. Besides, the current system probably doesn't have all the necessary data. For example, the in-store system probably does not have pictures of every item. Why would it?
The problem with LDS is that they are not stores like we think of them that stock products they owner thinks are best or whatever their business model.
In fact they are just showrooms for 1-2 manufacturers. This limits their selection and it gives away their intent.
Its the manufacturers' rules that are killing the LDS. Your charity to them by paying higher prices won't save this business model.
The shop I teach for has just about every brand I can think of. The only brand I can think of that we DON'T have is Sherwood. We are authorized, non-grey market, dealers for ScubaPro, Fourth Element, Shearwater, rEvo, Aqualung, Henderson, Bare, Waterproof, Hollis, Oceanic, Tusa, Apeks, Atomic, Dive Rite, Mares, Zeagle, Mobby's, DUI, Big Blue, Oxycheq (I think - at least, we used to be), Luxfer, Catalina, Faber, XS Scuba, and I'm sure there are others I'm not thinking of.
It has nothing to do with costs.
Most franchise agreements don't allow the local shop to sell on-line. If you were a ScubaPro or Atomic or Aqua-Lung dealer, and you sold those products on-line, you would not remain a ScubaPro or Atomic or Aqua-Lung dealer for very much longer.
The few places that sell a wide variety of gear online either have negotiated special agreements with their suppliers, or are selling greymarket goods (intended for export), or are getting their inventory on the Q.T. through another dealer, or a combination of these things.
I don't know about all that. I know the shop I teach for does have an online store (that is kinda sucky in the way that it works, but you CAN buy stuff online) and they sell pretty much everything online that we have in the showroom. I don't know why any manufacturer would care as long as the online prices are MAP or higher.