Quick Exhaust Valves are used in "Spudding" many people buy Quick Exhaust Valves (Or QEVs for short) to make air guns. Adding this item cheaply would guaranty many sales. The use of QEVs can be seen on the site http://www.spudfiles.com/spud_wiki/inde ... aust_valve which prooves that they are often use.
PS: The most used QEV is the 1/4" so thats the one which would guaranty LOTS of sales.
If lots of us do this then im sure they would add them to there site.
PS: i said price i would like to see is $1-$10