Basically, you gave the answer to yourself, the more difficult to do, the less competitors, and vice-versa.
Perhaps the best idea is to find a niche in the field of low poly, lets say, to model for Unreal customers, in this case I would look to find what these people buys and model for them keeping in mind to create new and exciting models.
Things are quite different if you decide to model for the screen, for example, where models have to suffer a close scrutiny, even so, you must choose a kind of models, let´s say, commercial planes, and focus on it.
Focusing in a choosen target it´s the key, if you offer quality, the customer will ignore the price.