louie wrote:
Why not a stainless wire-rope (cable)? A 1/8" diameter wire rope with
a breaking strength of 2100 lbs will probably cost around 30-50 cents
per foot (at least where I'm looking - McMaster Carr). That plus a few
clamps would probably do the job. You could probably even buy a
turnbuckle to make tensioning the guywire easy.


It's a lot cheaper than that if you buy it as
clothes line at a variety store or hardware.
Maybe $6 for 25-30 feet, may not be stainless but
most people don't need to last for 30 years.