In regards to the PVC pipe for a sail tube.

Not all suppliers are equal when it comes to odd projects. Many will give you a high price because they do not want to talk to you. Some, like doing this kind of thing, and will give you a better price or try to work with you.

Be sure to ask the sailors in your area where they bought theirs and if you can't get a lead that way, call several suppliers

For example, Moore Plumbing Supply in Houston has done this before. They knew what I was looking for. They offered a deal on some pipe they had in the back for $80 when nearby suppliers were asking $200

I now have a new high or low in sail tubes. On a trip last year, a guy was using about ~12 ft of a 17 ft Aluminum canoe screw to some plywood