I've had more trouble with my valve stems than most folks, I guess. Seems these are the source of most of my tire problems. They seem to be poorly made or made of too soft a material (the seal, that is) and so, I'd prefer not to be taking them in and out. Once I get them to actually hold air, I like to leave them there.
I use the KluneV deflators and yes, they too were expensive. Work well though...about 30 seconds per tire roughly, and you just rely on experience to get to the point where you only measure pressure once or twice during the deflate.
Funny though, deflating takes a few short minutes...re-inflating takes forever. For now, I re-inflate at the gas station, and what a PITA that is.