Having been involved in businesses that sell to the public in some manner since I was about 9 years old...
The point is that the basic premise of the OP, is a no show, period. Full Stop.
Sales to the general public, in audio, via a ’store’....does not work that way.
All scenarios are different, all scenarios change. If the store owner does not grasp that and grasp it correctly, and move with it correctly...then they die on the vine.
It will be tough sledding regardless.
Eg, in older times, an ’entrepreneur’ was considered to be about 50 years old. A point where a person was considered to be matured, tested, and varied enough to be trusted with the complex act of being an entrepreneur. To run, or head -a complex attempt. Nowadays... we somehow confuse this with 20 year olds, as if it is all gumption and running in place, expending energy. Walking down the hill (so to speak) is the best way to get it done. Still, to this day.
Finding the right level and quality of maturity in one’s self or another, is more the problem. Eg, you want to open a music shop, a record shop?... you want Richard Branson to run it. He has no more mistakes to make. At the same time he is learned enough to know he still will make them. Which begets the ability to correct with his vast knowledge base of how things can go wrong, a base of knowledge built out of massive levels of scar tissue.
To return the point, the OP is fundamentally flawed. It is a poser that is relatively meaningless and has no relation to the working functional world of such endeavors.