Ok so here are my first photos from my "shopping trip". These were all taken at San Gabriel Nursery, which I like because they have a wide range of material, from tiny starter plants to much larger multi-thousand dollar specimens. Each bonsai nursery in Southern California has strengths and weaknesses, and this one offers a lot of "rough" material that may or may not be a good deal depending what you can do with it. They offer a lot of material in nursery pots, which is fine for many people because they would rather not pay $10-$15 for a cheap pot they may not want to use, regardless.
My first "category" was to try to find starter bonsai material in the "less than $20" range - just to show people what you might be able to get for that price.
First up, a little Caitlin Elm. Elms are soooooo easy that should be one of the first (if not THE first) tree you should get for bonsai. You can pretty much do anything to them - cut them back hard, air-layer, stike cuttings, bend them all over the place, etc. Very forgiving. Plus they grow very fast.
Next up, a nice Shimpaku Juniper ready for squishing, twisting, or whatever contortion you had in mind. You would NOT grow a bonsai from this material without bending it first.
The classic Procumbens Juniper. Not my favorite because I don't like the foliage and the needles, but it is MANY people's first tree. Strong grower in a compact style - almost grows as a "natural bonsai". Buds back easily on old bark.
You don't get much of a Japanese Black Pine for $7.98, but this is it
If you don't want a long shimpaku to twist / contort, you can get a small one that has already been cut back a couple of times so it is more compact and has more branching.
They seemed to have a lot of Cotoneaster this time. A cute little shrub that is quite pretty and easy to care for.
Another of my personal favorites - Dwarf Hinoki Cypress. A beautiful tree when large with scallops of foliage and a dark red, heavy-featured bark. Somewhat slow-growing.
This was the best type of material in this price category, though they had other starter plants I skipped over because I didn't like the species

Nothing uglier on this planet than a $7.98 Ginkgo.
Notably lacking here (and in many/most other Southern California nurseries): (1) few Japanese Maples (you have to be REALLY careful with them or they dry up like a tumbleweed and blow away) (2) no White Pines (at least not on their own roots)(there ARE White Pines grafted on Black Pine rootstock, but the graft on most is extremely ugly) (3) No tropicals. Not sure why not (because you can certainly grow them here) but it may be that their clientele is more traditional.
I went to pick up a Yatsufusa Black Pine I saw yesterday and it was GONE. Grumble grumble.