I'm not trying to knock you here. I think that the models look really good. I think you are way overpriced on this though. First you have to realize that someone purchasing your models may not want to use all of the models, only some of them. Second you can't compare your price to that of having a contractor create models for someone. If I pay a contractor then the models created by the contractor become my exclusive property and can not be used anywhere else. Additionally the contractor is creating exactly what I want.
All in all these are good looking models. If you want to sell more you need to have a model pack containing a much larger variety of models though. Then you will appeal to more end users.