Sorry but it is certainly not worth $65 IMHO. You started by pointing out the 2 major problems - taper and nebari - which just happen to be probably the 2 most important features in JM bonsai.
Any tree has the potential to become bonsai but some have a much longer journey to reach the goal. I would not go back to that seller for more trees.
You have already spent the money so use your tree to learn with. Try out some of the techniques we use to correct problems - growing out, pruning, layering for roots, etc. In a few years your tree will look very different and could be way better than now.
Roots can be grafted to make better nebari or layer the area to get new roots entirely.
Taper can only come from lots of time or repeated trunk chops and grow.
@Adair M pointed out there may be some problems with chopping this one for taper so keeping it as a small tree may be difficult. Grafting branches or new leader lower could also be an option but all these will add years to the development of the tree.