In article , Sierra fisher
writes
HMG markets some tubes in
plastic, aluminum and brass that will give you a long lasting fly. Hobby
shops also have good materials for tubes. The sphagetti tubing tht you can
get from auto parts shops is great for 1/8" tubes.

Try using the plastic tube used in the production of cotton-wool buds.
After removing the cotton wool, bell the ends with a hot wire. These
little tubes make excellent tube fly bodies.

They must be cheaper than purpose made tubes for flies.
--
Bill Grey
http://www.billboy.co.uk