I'm probably going to come out of this like the Grinch who stole Christmas, but I am a realist, and if it walks like a dog, barks like a dog, I the kind of man who is just going to call it a dog.
The best time to start a bonsai business that is going to be profitable on a measurable scale this year, was 25 years ago.
In todays digital era, everyone has access to a lot more info and material then in the past. The trees that are selling for larger profit this year, are at least 25 years old in most cases. Sure, you can start some cuttings this year, grow them out for a few years, and sell them for a few dollars profit each 2-3 or even 5 years from now. But a persons time is worth money also. When you calculate the man hours invested into those trees, you'll be making about -$15 per hour (thats Negative 15). So there is no real money being made at all.
There are several nurseries who operate on a commercial scale, with machines and business processes that allow them to crank out things like 5-10 year old Itoigawas and Shimpakus for $30 each. Unless you invest the money in infrastructure today you're never going to compete, at least until 10-15 years after you get set up properly. Sure you can go get some Yamadori, wire them up and sell them for a little profit. but that's not sustainable.
People today, except those brand new to the hobby are wise enough to know, the best and cheapest way to get into the hobby is Yamadori. Or in other words, go to the woods, a local landscaper, or your neighbors yard waste pile after they rip something out of their landscape and find yourself material for your beautiful bonsai that has already went through the growth phase, and is ready for development and refining.
Throwing some wire on a few year old piece of stock and calling it a bonsai is the equivalent of a Mallsai. So even in that aspect, you cannot compete. There are several commercial nurseries who make those on huge scales already. They get their pots cheaper than you, their junk soil cheaper than you, their stock cheaper than you, can feed and water cheaper than you, can ship trees cheaper than you, and can do it all with a lot less labor than you because of their machines. They are everywhere online, and can sell mallsai cheaper than you can produce them.
I could really go on for days upon days here on this but I have about 35,000 trees to tend to today so i am going to wrap it up with a quick summary.
Bonsai is not a business you are going to start today, or even a few years ago that is going to be profitable any time soon. The profit margins on bonsai typically start at the 15 year mark for small operations. Being in a $500 refined tree, you have usually about $20-$40 in profit to be made after calculating in things like your wire for all those years, water, fertilizer, anti-disease measures like pesticides and fungicides, and labor @ minimum wage, for all the time you have invested into the tree.
If you are set on making money with bonsai, and you are less than 10-15 or even 25 years into your business, you really have only 2 options:
1: Become a broker
That is, buy some plane tickets, rent some cars, put on some miles, scour the country and find as many quality bonsai as you can for as cheap as you can get someone to sell it to you, then bring it back to your nursery, clean it up and sell it. I put on over 45,000 Miles from late January through last week on buying trips to find specimens in the USA. If I had any interest in selling any of them, I could certainly turn about $30,000 profit even after airfaire, rental cars, hotels, etc. But the thing is, I would have invested nearly $100,000 to make that $30,000 profit. I know of only 2 true bonsai brokers here in the USA, i am sure the situation is not too much different in CA. Being a broker is the only bonsai business model that you can start now and be sustainable within a year. That is to say, earn a living wage running your own business. You spend $X.XX on a tree and sell it for $X.XX, you factor in cost of acquisition like travel etc. and there is your profit. But it takes money to make money. There is a Bonsai broker who uses Bnut forums, most people already know who i am talking about, i'm not going to call him out here. but i am sure if you find him, he will answer some questions about it.
2: Bonsai pottery
People are paying sometimes up to 10 times more money then they have invested in their trees for the containers they put them in. I'm not giving away the secret sauce on this one as currently this is how I am turning profits to further fund our garden project without bleeding my retirement fund dry. But in summary, there is money to be made in bonsai pottery, and you can earn a living wage doing it if done right. You'll have to do your own homework on it though.
Conclusion:
If your trying to make money in bonsai;
DONT
Start a bunch of trees from seed or cutting and think you are going to make a business out of selling them. Unless you put no value on your time, you will not make money at this for at least 10-15 years.
DO
Start looking for bargains on quality trees in which you can purchase then sell at a profit.
Start dealing in quality bonsai pottery