You have mentioned the prices are so high for commercial bonsai .....how to avoid this for a beginner?
Prices for good bonsai ARE high, as are prices for good bonsai starter material. It takes years of growth and training to create them, so the prices are not so strange.
However, there are loads of shops that sell mallsai, and plants like yours, that are essentially not bonsai, but labelled as such. Sometimes I think I should change my career and start growing and selling it. Label it bonsai, quadruple the price.
Best way to get good material is:
- Grow it yourself
- Get material from nature (make sure you have permission), from gardens (my juniper comes form my parents' garden, from areas that are being cleared out
- Buy (non-bonsai) nursery stock that is suitable
- Buy pre-bonsai from a real bonsai-grower
(first option the cheapest one, the last option will be the most expensive)
Also, you could join a club, trade, buy at club-auctions.
This website has a list of clubs for each region. Not sure where, you'll need to look it up.