The background is really two different items.
The far background is 21' of gold lame' fabric I picked up at a fabric store locally for about $2.5 per yard. I clipped it onto a background stand that was positioned about 6.5-7' high and draped it up and down until I was out of fabric and then fooled with it until it looked kind of right. I still want to tweak it a bit.
There is also some additional gold to the model's left. That is an emergency "space blanket" that I purchased at the "Sport's Authority." This is the cheap one, about $5 and pretty much looks like a 5' x 7' mylar sheet that is gold on one side and silver on the other. I have it taped around an 8' high cardboard tube that is 12" in diameter.
I also use these cardboard tube to bungee cord some white corrugated roofing panels to and create a column look for my white background paper.