I don't see what the big deal is for making your poster free. I make 3d models myself, heck I even made a Berserker model. however he is DS specs but none the less, if anybody wanted him as a poster size I would give it to them...Just I wouldnt be making the poster, they would have to ;P
Grayscale : it is work. Work is work and you can feel free to give your time to people if you want, but don't judge me if I want to earn _ridiculous_ money, just cause I think all work have to be payed. Thanks for your interest. (in fact, I'm not pretending to sell anything. It is just fan art, for my own pleasure first.)