I've just spent 4 hours with some 20mm/OO scale steel security fencing from Knightwing International. I have built and measured for use, 6 feet of the stuff in that time. That includes building the hinged gates etc.
I don't think that's bad at all.
I paid £24 for 78 inches but you can get it in 26 and 52 inch packs too.
It's great for 20mm scale figures where you want 8.5 foot high fencing, but it would work really well for 6ft type that you see all over the place, if you were wanting something for modern, zombie or post apocalyptic type games in 25/28mm.
The mouldings are sharp and clean, and once you have built a couple, it's simplicity itself.
There's lots more stuff on the site, but the fencing can be found here: