The sword cost just a few $, made primarily of PVC piping from your local big box. The blade is heated and flattened 3'4" schedule 40 PVC pipe. Surprisingly sturdy and pleasing end result.
Step 1: Ingredients
1" PVC grey pipe (about $1.25 for a 10' section).
1" PVC end cap (about $0.50)
1" PVC coupler (about $0.50)
1" to 3/4" reducer coupling (about $1.30)
PVC cement, PVC cleaner (found in plumbing aisle - I already had this)
PVC pipe cutters (or hacksaw or saw)
Black duct tape
Heatgun (you could also use a propane torch, but it's easy to burn/blister the PVC, and you can't sand out the brown stain. Been there, done that)
Rubber Bands (I went to my favorite big box stationer and found a bag of large red bands, and another bag o' green ones - the preferred colors of Thing One and Thing Two. Bargain).
Step 2: Pipe Cleaning
Step 3: Forging the Blade
Squeeze it flat in a vise, a section at a time. Practice with a scrap piece first...you'll get the feel of it quickly..
I really liked the taper on the blade that I was going for. The end result was a flat and strong blade. I was happy.
Step 4: Assembly and Finishing
Glue two pieces together at a time - brush glue on outside of pipe/inside of coupler - push all the way in, twist 90 degrees and hold for a few seconds until it sets.
The end cap was white (all I could find), so I covered it with black duct tape. Purely aesthetic.
Cut a rubber band and start winding it onto the handle. When I got to the end of the band, I tied another to it and kept winding, winding over the tied ends and knot. Repeat until you reach the other side, and tie off the band. The whole handle was wound fairly tightly, so I tucked the loose end under a few turns to hold it tightly.
I was going for a raw functional look, so didn't mind the knots etc. on the handle - made it look Ninja-ish to me in a weird way.
And there you have it...a sturdy sword that will withstand some boisterous dueling, nothing sharp about it, that will definitely come out on top against the cheap costume swords out there.