Good exersize. Now go to your trees and take half of tham that you are least happy with. Decide whether each tree has enough going to keep. If not, sell or give away. The money you get for it, become the money for a better tree.
I try and do this once a year. Typically after visiting a major show. I unfortunately still have way to many trees that will not become bonsai, but have meaning to me. But the average boring nontrunks.. they move on.
I think it is easy to come to the conclusion that ones own trees are below average, not worth the effort etc. Important to realize: growing bonsai takes time. So do not judge the now, but the 5 or 10 year potential, linked to the work needed to make it a bonsai.
I think..