I once designed glass pipes for a school project, and getting them blown by hand in clear glass was very very expensive.
Until I found out about borosilicate glass. This is the material used for lab equipment. The raw material, borosilicate pipe, is more expensive than glass, but blowing and shapping it is a lot cheaper. And borosilicat resiste extreme temperatures well, you can just drop it in boling water to clean it.
Going to a lab supplier instead of an 'art' glass shop saved me more than 60%.
The shape of the lilly pipe should be quite easy to make, and the intake pipe is easy to seal in the end with the nice hemispherical cap, the slits could be expensive.