I can answer for certain with Chili powder, and from that I can make some suggestions. When I bought Gebhardt chili powder and compared it to the bargain basement powder that was in our pantry by taking a taste of each, I was astonished at the dramatic difference. Frankly whatever was in our pantry had a mildly rotten taste, along with a lot of heat. The Gebhardt, on the other hand, was a distinct flavor, with a lot less heat. There are other ways to add heat, so I thought that was well worth the price difference. (I'm sure chili experts who make their own powder can do much better, but I'm very much a novice).
In general, I would recommend that you double costs now in order to make good economic decisions later. We bought two kinds of chili powder, cheap and expensive, and from that could tell one made a huge difference. We will probably continue to go with expensive chili powder. For other spices, maybe less so, or maybe some cheap brands do better than others (target's house brand is one my wife finds to be reasonable quality / price compromise for us).
Pay a bit more now, and buy both for a few spices you care about. Taste them both. Over the rest of your life you will then know the answer and know what is a good compromise. It is a small cost for what amounts to a lot of future purchases.
If you go expensive, maybe also proceed with caution. Buy both of some other spice. You may find that some spices are easier to "get right" and a cheap seller will do. Please repost anything you learn here for the rest of us.