Actually, the prices on those imports are quite reasonable. There's already another thread on this board discussing these trees and prices, so no sense rehashing it here.
There are different levels of bonsai hobbyists. Some people want great trees. Other people just want trees. Sometimes "want" isn't the issue and "afford" is the issue. Whatever the situation, high quality trees are expensive, either through the money you pay to buy one, or the time and effort you spend to create one.
There are 2 givens in this hobby: 1. Good bonsai don't grow on trees; and 2. You don't need good bonsai to enjoy bonsai as a hobby. To the second point, there are many people on this forum who enjoy bonsai but will never have a single good bonsai. That doesn't mean they should quit the hobby.
Here's a Japanese Black Pine listed for $6800. Is it worth it?
Try growing one like it and then answer.