Which product number/valves are you ordering and using, specifically? I'm trying to split up my CO2 into 3-4 different tanks, and saw where you were using Clippard products instead of items like the 4Plex manifold.
Bought them at a local distributor for less than $5 ea. and am very happy with them.
If you click on distributors and type in your zip code, they will respond with the one(s) closest to you. Make sure that you pick up a pack of screw-in nipples as well. They don't come with the valve.