Ok, I missed the stretchy incident in the original post, lol.
Looking at mcmaster, both the 1/2ID 5/8OD variety of food (B-44-4X) and lab (R-3603) grade tygon are under $2/foot. It's the second item down:
http://www.mcmaster.com/catalog/108/html/0083.html
Also, the manufacturer has a chemical resistance chart that might be helpful to the curious here:
http://www.tygon.com/chem/chemafrset.html
I think I'll try some of this over more silicone. It seems interesting.