You may want to check out of what's available at your local box stores.

Here is a link that might be useful: Containers

Repurpose, repurpose, repurpose. Look for people throwing out old ones and paint them, call businesses that use large containers and see what they do with they discard barrels, wooden boxes, etc. With just a little work a few pallets can be taken apart and reassembled into a great planter box. I go up and down the aisles at the big box stores looking for products meant for something else that doesn't carry the premiums of the garden purposed products.

Hope that helps at least to get you thinking where you may find some in your area.

Here is a link that might be useful: Heath.fm

My wife and I have been all over the B'ham area shopping for large cheap pots for our Sago's but not much out there in the cheap range. Old American store has the best prices we have found in the mid to small size range. Tsitalia in downtown B'ham ,to me, has the best prices on large pots but they are Greek style pots.

Old Time Pottery in Pelham has about the best prices on large ceramic containers that I have found in B'ham area. For a really big cheap container I would go to the coca-cola bottling plant (near the airport in B'ham) where they will sell you big plastic food-grade 55 gallon drums. (many people use these to make rain barrels) You can cut the barrels in half to make to big containers, and you can spray paint them any color if you wish.

Great tips. Thanks. I think I'll check out Old Time Pottery.
The Greek place got me thinking, there's a Mexican import place behind the Summit--Yucatan or something. I think I'll check that out too.

The ice cream store here gives away the large ice cream buckets for free. You have to wash them out yourself and drill holes in the bottom, but their free. Also, used 5-gallon paint buckets are so many places for free. Have you posted an ad on Craigslist (under "items wanted")?

Edit: "but they're free".

I bought some smooth-sided black 20 gallon containers from the nursery I frequent here in Mobile. Laura Kay's nursery on Cottage Hill, will sell some of their large plastic pots. Just ask Mr. Nick.

I also buy terra cotta pots made in Viet Nam from them. Not as cheap as the black plastic, but it depends on how decorative you need to be. The ones I got last year did not crack or chip during our cold winter, so that was a big plus.

Have you tried a Hobby Lobby Store? They have a garden section and every other week the pots are 50% off. Also, they will soon be clearance out that section because its in the space that is used for xmas and they start setting up their xmas in June.

Here is something on my "gonna" list that I hope to get around to doing soon. I really want some large, attractive pots, but would rather spend my money on plants :)

Here is a link that might be useful: hypertufa pots