I guess anyone that keeps 1,000, or 2,000 kits is their business. To each is his own. I personally don't understand this but that is just me.
I've been modeling since 1977 and I only have 15 or so unbuilt kits in my inventory and they are all special kits.
For most of these years I would have no stash at all. Build one then buy the next one.
Kits are crazy expensive now. I'll buy the Hobby Boss M1070 plus finishing supplies and figures is $250. and that is one kit with Black Dog figures. I have the Trumpeter Leopold in 35th scale with two boxes of figures. The Revell Germany 72nd B-36 with the special decal sheet.
These kits are special kits and that's why I will buy them to build at some point.
I always liked the Verliden Napoleonic 1/16th figures which are pretty incredible. Now he is out of business so I will probably buy several of them before they dissappear.
I will also never be working on more than two models. One being a years long build like the Revell 1/400 QM2 ongoing, and a few smaller builds per year while that long build moves forward.
Hey, whatever works for the individual.