It's been a while since I checked. It was a little pricy but when you start buying pipe fittings they add up more then you expect some times too. We used the 3/4" flexible line. We have several pices of equipment and we are running a water table which elevates with air. The 3/4 was nice for large volumes. Most peple don't need anywhere near that but the whole process was....easy. But...if you buy the wrong parts, then it can add up pretty quickly.
Just about everyone handles them anymore.