Elliots is great when you need something quick. They have a great selection of things that HD and Lowes don't carry. And they are open on the weekends.
If you need more in the future and can make it down there during a weekday, Allied Plastics has the best price on the tubing out of all the places I called around town. They will come in around half of what Elliots charges for it. Most of the other plastic suppliers were a little higher.