I think there is a difference here in some of the retail comparisons noted above. While yes the mindset of a sale or deal generates more sales you are comparing coral prices to consumer goods. The price for coral is purely set on rarity and popularity (look at the price of torches over the last 12 months). There is no assigned cost plus M/U (Like clothes at JCP), fair value is based on what the market pays. Therefore the pricing tatics used to influence sales (increase the price of my GSP to $100 and "discount" it to $25) based on perceived value can be dangerous to some people who don't know how to value GSP (same arguments made with less known SPS and no one knows what a fair price is, making the perceived deal more lucrative). Combine that with a panic situation (first to checkout) and you have these types of business practices.
And yeah, its good on the stores of finding ways to move product they would have a harder time selling... Is it in the best interest for the hobby and fair honest business, idk....
Selling something is selling something. And companies who even sell goods often set MAP pricing so that they can reduce it for black friday and other sales. Adjusting your pricing to make money and make people think they are getting a good deal is the same regardless of the product. And anyone is free to frag and buy from reef clubs if they want. And when you buy coral from a distributor you are also paying for their gas and equipment and sometimes even their dive team. which is why it is often cheaper to buy at a frag swap. It's up to the consumer to research and see if they feel a particular vendor is selling something for a fair price or not. If not look else where.