It was very cheap to create, I spent no big money in buying the fabric, the synthetic leather, hot glue, cheap wood for the rifle, a pair of worker's gloves... Less than 40€ I think, (about 55 US $).
Note that I haven't finished the rifle yet, made of wood, it needs more details. Also, the bandoleers don't look as perfect as I wanted, because they were made very quickly (I needed to finish the costume for a convention). The best would be to buy the bandoleers instead of making them like I did, but it more expensive.
The process need sewing abilities, a lot of hot glue and a saw for making the rifle, but it was not very hard. The hardest thing was making the helmet/mask, which I created modeling the whole head in clay and then covering it with paper and glue, then covering it with the fabric and the other details.
I have to say that my costume don't pass the 501'st legion standards, but it's not too far away. I'm even thinking in fixing it so I could enter the 501'st, maybe one day I'll do it.
You can see the costume "in action" right below:
I'm sorry I don't have pictures of the making process, the camera broke after taking them, so I can only offer you the final result. I hope it can be used for references.
Thanks for watching and sorry if I committed any grammar mistakes, English is not my mother tongue ;-)
EDIT (15-10-10): I've taken a few pictures more, for showing how some of the parts are separately.