You don't even need to own a spice grinder; just add the whole spices to a high-speed, good-quality blender, and let the blender do the work. It will grind the spices into a fine powder ...

you should buy your spices from a high-quality purveyor, keep them in sight so you employ them regularly and toss them within a year of purchase. Judicious advice. Even more expedient, perhaps ...