Three Chinese Elms I bought for €7 each 2019. re potted today into a pot that I took to the trophy to sell and no one wanted it. I think it’s the perfect match.
I agree that good bonsai can be made from inexpensive material. Looks good and I like the pot (surprised it did not sell). I would prune the side trees (particularly the left one) back a bit and allow the center one to grow. The trunk spacing is a bit too uniform in my opinion and I think the foliage can be developed to make it look less uniform.