I also agree with Graham, its not a money spinner and is a serious issue.
Although I've been using cheap GSF R6 hose for 3-4 years now, on my old beetle and now in my bus. I've yet to notice any of the lines going brittle or cracking, the ones in the bus have been in a year and a half now.
I do use copper pipe for at least 80% of the line though, only using the hose where connection to barbs are required and where many bends are made.
I personally think we should all be using proper hard lines with compression fittings at fuel pumps and carbs etc, probably wouldn't cost much more than the proper ethanol rated rubber line!