Rick wrote:

snip

I suggest you pay extra and get the lightweight ones, cause its gonna
save you pulling your back.

I second that.

I've just removed 12 of the eight foot ones, which had lumps of concrete
on the bottom. I took the option of breaking them in half, and
angle-grinding through the metal reinforcing bar to make them more
manageable (ie: luggable into a skip). These were 18 inches into a
block of concrete, which measured about 20 inches deep and about 12
inches diameter. They were supporting a six-foot fence panel: they blew
over earlier this year, even before the panel popped out.

Regards
Paul