I now have a spice cupboard! Yes, in the recent remodel of my home office/pantry, a re-purposed bar and entertainment center yielded a spice cupboard among other things. Why do I need a whole cupboard for spices? Because you never know when you might need marjoram for the chicken salad, celery seed for the coleslaw, or cream of tartar for the snickerdoodles.
Stocking a spice cabinet can be an expensive proposition but not if you spread the project over a lifetime of cooking and travel -- interspersed with trips to the local ethnic markets, health food stores, and even supermarkets.
Buying Little Bits in Bulk
If you stop to add up how much bottled spices bought in the grocery store cost per pound, you will consider storing them in the safe deposit box! The supermarket is a very convenient place to buy spices but once I have that nicely labeled container, I refill it with stock from cheaper sources. When your cinnamon bottle is empty, don't buy another bottle. Buy bulk cinnamon from the health food store or look in the supermarket or taqueria for cinnamon in plastic bags. Much cheaper. When your oft-refilled bottle starts to look seedy, buy another bottle.
Spices as Souvenirs
I've bought spices as souvenirs since those days when the only travel I did was to visit friends or attend professional meetings. I would come home from seeing Boston friends stocked with goodies from the Italian North End. My gumbo file was my souvenir from a conference in New Orleans. Souvenirs help us remember our journeys. Why not spice up a trip to visit the inlaws with a stop in Cincinnati at Jungle Jims, the world's largest grocery store, to restock that wonderful lemon pepper or find a disposable grinder full of nutmeg bits? If a friend asks you what to bring back from their trip, ask for spices, especially if that trip is home to a foreign land. I will never know what was in those wonderful spice blends brought to me from a mother in Israel but, oh, they were delicious while they lasted!
Oh, and yes, though freshly purchased and ground spices are best, you can keep most spices for years if they stay air conditioned. Just use more. When they lose their taste, throw them away and start over.