I tend to agree with Chris here, you may be wasting your time on this one.
The two biggest problems are almost impossible to correct:
The first one is the rootage. Not so much that they are tangled, but the way they are tangled. They seem to show a reverse taper, sort of inward curving into a ball. Very hard to correct.
The other problem is the branch placement. If you intend to keep the tree more or less this size, you need a more balanced branch arrangement. Otherwise, the tree will always look immature. Unless you graft some branches, this is a tough problem to overcome.
So, for 5 dollars, is it worth to take on these problems, or would you rather get something with good roots and plenty of branches to choose from. I would rather pick a young seedling with perfect rootage and overabundance of branches. With this kind of young material, time will only improve it.
But in your case, time will not improve neither the roots, nor the branch arrangement. So, you may end up spending the next 15 years on creating a mediocre tree.
Edit: you may argue here that the talent of the artist lies in creating good stuff from difficult material. My take on it is that the so called "difficult material" has to be something that has so much character and interest, that it is worth the challenge. But often, we have difficult material that offers not much else but difficulty. These are better off left alone.