It's always such a bummer when you finally muster up the will to try a recipe only to find out it calls for some random spice that costs $6 and winds up sitting in the cabinet covered in dust. I usually wind up either ditching the recipe all together or forgoing the spice and making a dish that tastes like salted cardboard. This is why, after pouring over many a recipe, I've come up with the 10 spices most seem to have in common and everyone can invest in with peace of mind.
In order of importance:
Good quality sea salt – I like Celtic Sea Salt or Redmond Real Salt
Italian spice blend (oregano, basil, etc. – no need to do it yourself, the premade ones are cheaper and do the job)
Nice herbs to have:
Rosemary - you can literally throw this on ANYTHING and it tastes 1,000 times better
Basil - apparently the plants are very easy to grow (can't say I've tried myself, but I'll keep you posted...)