If someone was going to gift to me the initial startup costs, I think my shop would be a little like this.
First, I would have a shop that would provide all of its energy requirements from solar panels and be able to sell some excess electricity to the local grid to help with dry goods and water.
The shop will have a 10k gallon display tank cram packed with the most colourful and rarest Softies, LPS and SPS colonies that could be fraged from to supply all coral stocks. Clams will be imported on request of the customers and anemones will be grown and split in a separate display tank.
Ofcourse, we need somewhere to put all the frags to heal and to display for sale. So, a 5k shallow tank will be used to display healed frags and colonies and also newly cut frags that can be reserved buy customers for a small deposit.
The latest and greatest dry goods will be on display along the perimeter of the shop with the frag tank in the middle whilst the display is on the back wall.
Since all coral will be frags of colonies and the upkeep non existent, prices can be very low and dry goods can be sold at bulk prices.
There will be also another tank (somewhere) where as many fish species can be bred and sold again at very low prices.
Hmm, now only if someone will pay initial costs...