The title kind of sums it all up. I am looking to purchase larger quantities and hopefully pay a little less for some spices. Paprika is one. All you can get are tiny jars at the grocery or buy it in bulk (not really “bulk” but scoop-it-yourself) at the co-op where it is super high quality and very expensive.
Any thoughts?
You’ll probably get recommendations for Penzey spices.
I buy most of mine at the grocery store, or for Indian and middle eastern, we’re lucky to have some excellent “ethnic” grocery stores around here. For oddball spices (eg berbere, dukkah) I really like zamouri. I don’t think they’re that cheap, though. But I’ve been very happy with everything I get from them.
I used to order from Penzeys when there wasn’t a store nearby. You can also order from Savory Spice Shop, which I can also recommend, since there is a retail store in my neighborhood. 
There are probably other bulk spice shops that are cheaper, but they may not have the freshness of the above two. You really do get what you pay for.
La Tienda sells Spanish smoked paprika that is very good.
Penzeys!
I can highly recommend The Spice House:
They also have retail stores in the Chicago area.
I’ve been to the one in Evanston and it is really, really cool.
If you sign up for their mailing list, they sometimes have offers like free shipping and invitations to talks by experts.
Second The Spice House. The founder was on the Alton Brown podcast a while ago and talked about the different grades of spices and how getting reliable supplies are tricky when most of your vendors are in the developing world. They seem very knowledgable and passionate.
I ordered some Sichuan Peppercorns from them that were like nothing I’ve ever had before. A single corn, chewed raw had my tongue tingling for a good half hour. Everything else I’ve ordered from them has been great as well and the green harissa they sell is ridiculously good.
eBay and Amazon.
I like this place. High quality and organic.
Thanks for all the links. I’m going to check them out. 
I just ordered ~$120 from The Spice House last month. So far, I’d say they’re…ok. Not the best prices, but a little better than grocery store, though I forget how shipping worked out. I’d give the roasted garlic powder a miss…I have to use so much it almost acts as a thickener. The “European Basil” is awesome, though, also the (Turkish?) bay leaves, and so is the Greek seasoned salt. The cumin I ordered is pretty good, too; I forget the exact designation, and I have repackaged it in my own container, sorry. Don’t bother with the dried chives–no flavor whatsoever.
Anyway, those are the standout hits and misses for me. I think I’ll try Penzey in a couple months.
The 4 on-line spice merchants I have bookmarked on the computer are Penzeys, The Spice House, San Francisco Herb Company, and Pendery’s. Each has their strengths and weaknesses. Sample, compare, enjoy.
But Penzeys gets the bulk of the orders by far.