I also dont think that 150$ is a lot. And I am interested in this, but the current system is not yet at the quality that I would be willing to buy.
No matter how great your customizations are, your base mesh isnt something I would put into my project. And since you dont seem to want to create qualitative skeletal meshes, I must ask you: How easy would it be to use my own skeletal mesh? Is it as easy as: buy a character from the marketplace and plug-in-and-play? Or do I have to set it up in a 3D modelling tool prior to use with your plugin?
Because if I have to touch any external software at all to get your plugin to produce some good quality stuff, then its a failed product from my point of view. I dont know how other people see it, but if I would have to set up morph targets or whatever for a skeletal mesh in order to customize it with your system, your plugin is nothing more than a customization interface. And in that case, 150$ would be too much for me.
And on another note: Is it possible to save a character created by your tool to hard disk and theoretically even load it at editor-time?
But this asset looks very promising, so I hope you will shape it up some more. A male mesh would be welcome as well, since its customization would be a little different than the one for female characters (since males dont have breasts for example)