Just a quick note...
I just received my fuel line order from Aircraft Spruce and Supply and can see no difference between their "generic" translucent blue polyurethane fuel line and the Bing blue fuel line. They come marked with different part numbers and if the Bing stuff wasn't marked "BAI - URETHANE" every so often I'd not be able to tell which was which. That might be why the price between the two is so close, only eleven cents more for the "Bing" stuff...