I just recently did the fishnet shirt for a Deidara cosplay, also. I couldn't find any fishnet fabric at my local fabric stores, and I didn't want to order it online. So I went to a craft/home supply store and bought actual fishnet that is meant to be used to hang on the wall or something. It was brown, so I spray-painted it black and then made a shirt out of it. It was cheap, which was nice, but I found it difficult to work with, because you can't just sew the seams like regular fabric. I carefully cut and then glued each knot together, which worked fine but took a long time. The net cost me about five dollars. Just an idea to help minimize cost.
"Shyness is a curious thing, because, like quicksand, it can strike people at any time, and also like quicksand, it usually makes its victims look down." ~Lemony Snicket