This is by far my favorite costume I've ever made. I made it for my husband, who really resembles Karl Urban.
The helmet is craft foam and paper clay.
The harness is fabric.
The shoulder and wrist armor is cardboard, fabric and craft foam.
The chain maille is fabric... sorry no close ups for that.
I don't think I ever made a thread on this costume here, but I do have a tutorial on my website: Eomer
EDIT - Because I didn't read the 'read this before you post' post. *hehe*
What inspired you. - I love the Eomer character, the costume design and Karl Urban (and that he looks like my huz). I don't know that I would have tackled it had those three things not all been there.
How long it took. - It's been so long, I think it took a good 6 months, but that was off and on work. Most of it wad re-engineering the design to figure out how in the heck to do each piece. The pauldrons pattern took the longest, then the helmet.
How much it cost. - because of the materials I used, it wasn't very expensive. I found the fabric for a dollar a yard and the craft foam is very inexpensive. I'd say it was easily $300 or less.
Specific details for which you are most proud. - The helmet I think is my favorite part of the costume. The way the horse turned out when all I used was paper clay amazed me. I also loved the use of paper brads (fasteners) that I got from the scrap booking section of Micheal's Craft store for rivets. It's finding such details that work to fool the eye that really get me excited when making a costume.
Tips. I have a tutorial to this on my website - link in my sig.