I got all mine from Grainger. I'm willing to pay a little more sometimes if I am impatient and don't want to wait for something to be shipped. Mcmaster Carr and others if you are patient.
It's a shame you just missed the lot that I had ready to ship. Just sold out today. The key is finding decently priced stainless compression elbows. The polycarbonate can be bought at Mcmaster.com