Have you ever bought new items to hold onto and then sale on Ebay? Some can suprise you, I have bought Charles Wysocki puzzles new at a store, and put them away on a shelf for several years and sold them for 4 or 5 times what I bought them for.
Coming from a manufacturing / operations background, to me inventory is evil. It ties up cash and space, it gets lost, it goes stale and out of date. If I can't flip it, I walk away. But I am the exception -- I stand in line at estate sales with dealers renting storage units to hold all their stuff.
I'm mostly the same way. I try to keep inventory levels as low as possible.
It depends on how much cash you have available to you (cash makes no money). If you can make 50% to 1000% on the items you buy with cash you would be crazy not to stock pile. Better than any savings account, bonds, 401k's, retirement plans...etc.
Even if it took a year to sell.... where else can you get 50% or more on your money. The guys that stockpile understand this and have the cash.