I'm in the minority, I don't have a stash. Well, I have 3 in my closet waiting to be built, but that's it. They were given to me the past couple of years as Christmas gifts.
For me, the hobby shop is my stash. When I complete a build, I then go to the hobby shop (or ebay) and find a new kit for my next project. I really have no desire to collect the kits and have them sit in a closet. That's just me though, I realize I'm in the minority!