I try to start out the same thing but on a smaller scale. I think it makes no sense to compete with what is already sold at every corner.
I think cuttings are good but if the niche you choose requires seedlings too then you will have to do seeds too.
I start really slow and relaxed, so every time I am weeding I do some layerings. I plan to build a bed for the cuttings now.
I want to do herbs and food plants (but not the grafted trees). That is something that actually could appeal to an upmarket too.
I was looking at
local retail nurseries and what they don't have.
For the setup of even a small nursery there are three main problems the setup, shadehouse were do you put your pots etc?
The potting mix and who will mix that? Keeping track of all the exact names of plants in your garden how they are used etc and putting a label on each and every plant you sell. Unfortunately I don't have cheap sources for that.
Water and the misting system for cuttings (if you are technically challenged).