For my windscreen installation I bought two tubes of 295UV, and used slightly less than one overall. Even though I wasted one tube I'm glad I had the second one, since running out at the 90% mark would have been disasterous, and the material is not that expensive in the grand scheme of things.
As for the other components, with both 205 activator and 209D primer a little goes a long way... a 250 mL bottle of each will give you enough for multiple canopies.
