I too have often thought about cheaper alternatives that are safe enough and have the quality needed to stand up to the rigours of flying. I have been reading these posts with interest.
As a point of interest, what would be wrong with using airlines as used on trucks, I have used and installed these lines before( on trucks that is ) and have noted that most times they get covered in all sorts of gunk from deisel to corrosive chemicals, get banged arround, shaken, rubbed and pelted with rocks and stones and still have to hold air pressure.
A cheaper alternative with a proven track recored?????