Some excellent information above!
I actually did consider the PVC pipe. Two problems: I was anticipating mounting a small piece of plywood on the rack to hold a 3-gallon plastic container, and didn't see a convenient way to attach to PVC. And, I didn't see a convenient way to make the attachments to the bike- still have to transition to metals.
A rack about a foot longer would have been nice. I was planning to put a container on top, not hang panniers off it, so kicking the load shouldn't be a problem.
The carbon fiber and titanium sounds good...this is going on my Worksman Industrial Bike, that would be great! (Some day, I'd like to order a custom $10,000 racing bike and then as an afterthought, ask them to mount a big front basket on it.)