Hm, some very interesting opinions and hypothesis here in this thread, might as well add my 2 cents!
As someone who worked in a popular LFS over 10 years ago (they are still in business too!), I would say that equipment costs have not really changed that much. There is, however, newer more advanced equipment that does cost more (MP10QD comes to mind). At the same time, there are other new products that are still relatively affordable, like the Icecap gyre pumps. Now, I have to add, I remember when the Hydor Koralia powerheads first came out, and they are still the same price today, as far as I can remember...same goes for the Aquaclear HOBs, just to name 2 common and popular products.
Now, you all have mentioned how buying dry goods online is killing LFS everywhere. I would have to disagree with that. Markup on dry goods was maybe 10%, we were never encouraged to push hardware/drygoods on customers, because that isn't where the shop made their profit...however, livestock is a whole other story!
Typical livestock markup was between 300% to 400%. Not only is this where the LFS makes the vast majority of its profit (followed by maintenance services, and probably water after that) but it is also the biggest part of the risk.
Our first task every morning was to remove the "deads" before the shop opened. We would easily toss at least $500 in saltwater vertebrate livestock every morning...sometimes it was worse! This does not account for freshwater, but there was probably close to 3% loss of livestock daily there as well, best estimate.
Now, let's talk about the increase in livestock prices! As far as vertebrates go, some are cheaper now than what I remember, while few do seem to be more costly. Oscellaris are still around $20, goby/pistol shrimp pairs have gone up, but not by much. At the same time, some fish that used to be rare (signigobius biocellatus for example) are now fairly common and inexpensive. Speaking of the 2-spot Goby, back in the day, I searched every order form for over 6 months waiting for one to show up, and when it did, I believe I paid $40, cost...this translates to over $100 retail after markups. Recently, I stumbled across these enchanting little devils for $20 each on LiveAquaria!
I notice the biggest price increases are with coral. Best example is mushrooms, like when did these get so popular!?!?! Most of my customers would not even consider adding mushrooms to their mixed reef because they considered them a nuisance...now we have people spending hundreds of dollars, per polyp, for some of these color morphs! Another huge disparate in invertebrate costs are zoanthids. These button polyps used to be super cheap, and as they are now, a go to for first corals. The only named morph we had back then was "Fire and Ice", which were actually stupid expensive! Even with my cost being wholesale, I could never afford the "Fire and Ice", not even the smallest of colonies (before frag plugs too). I was so excited to pickup a small colony at Florida Frag Swap earlier this year for $15!!! The biggest difference with zoas now is the variety of color morphs, and the cost of some of the more popular ones. We used to get F&I or brown...hahaha...so many brown corals! A lot of other corals seem to have changed in price as well, some things you used to be able to buy a proper colony for the price of a frag of the same today, but I think this is OK. I prefer to buy small frags over colonies, the grow out is so much more rewarding! More importantly, the frags have been grown out in captivity and have much better survival rates, very few corals were aquacultured 10 years ago. I'd rather pay a little more for better survival rates, I don't know if that should be considered a cost increase.
So, I believe the changing prices in our hobby is not nearly as vast as some are making it out to be. If anything, I believe it is cheaper to setup a proper mixed reef now than it ever was before, especially with the advancement of LED lighting. Although, like most things in this world, you can definitely break the bank depending on what equipement you choose to use! You could do the same way back when too, don't forget that metal halides and chillers used to be the norm if you wanted to keep any SPS!
Not everyone needs a Ferrari for their daily commute, most are happy with an old pickup truck...happy reefing!