I rather like your 2D work... you obviously have the technical skill and the work is generally well done with interesting themes and decent composition and color choices. The only flaw might be that perhaps it looks a bit unfinished. I think to improve it you should try posting it on the more serious art sites so you can get feedback on how to polish it even more. I'd recommend conceptart.org for one...

About your poser/3D stuff i agree 100% with Acadia... Because of the nature of 3D art, it takes a lot of efort to make it look as alive and attractive as other forms of art. Straight renders rarely look different or appealing enough to be something a person would want to buy... esp when the same characters and settings are seen again and again in the galleries. A bit of postwork can help sell your renders so its definitely something to try out.