I guess there are some spices that cost the same as a week of food, but I don't think there's anywhere on the globe where that's true for everything that falls under the "spice" umbrella. A box of craft dinner is about $1.10 where I live, a 1oz. container of dried thyme is about $3.50, which is fairly typical for grocery store spices around me. There are spices that are very expensive and those are out of reach for a lot of people, but I think most almost everyone has access to some cheap spices.

A lot of them are easy to grow / are invasive species that are hard to stop growing: I have mint in my yard and I'm not sure I could kill it if I tried. Every year I cut it back and every year it grows back strong.