At my local nursery. They bring in container loads of frost proof, glazed ceramic containers from Vietnam a couple times a season. All shapes, sizes and colors.

"Great prices"? Maybe not :-) These are not inexpensive items but they do have a special sale on them now and again at 45% off. And I did score once when another customer (with big bucks) redid all her containers in another color and sold her slightly used ones back to the nursery........I bought 11 of these in my colors and with matching patterns for less than 50% of their orginal cost.

There is also a wholesale garden pottery distributor nearby that I can access but I usually reserve them for clients.

I never do concrete.....it is just too heavy.

Local nursery, but I have to shop around/look for sales as well. There is 1 LN that has decent prices, one I wouldn't shop unless there was a sale, and one I wouldn't shop at, period. The last one has pots for $79 that I could get at the other place for $29. I occasionally shop Ollie"s Bargain Outlet when they get a fairly big shipment... Lots of UGLY pots though!

Though it is very hit or miss, check out estate sales or CraigsList. You might also want to peruse a HomeGoods Store or two (they tend to get a huge number of pots in this time of year).

home goods had a pretty good variety early spring...

I also shop at a local nursery which offers a buy one/get one sale once or twice a year. My advice is to buy one or two large, good quality pots each year and over time you'll have a nice collection. Consider pot colors carefully so they work together and you can change them up. Agree, too, that estate sales are good places for bargain pots -- sometimes they even come with a plant.

I live in the back of beyond in rural Canada, with no estate sales or good quality nurseries around me; I dream of one day driving to Detroit Garden Works : ) .

We had a local hardware store (since closed, sigh) that carried graduated sets of glazed pots from Vietnam, as gardengal mentioned. I bought three sets about 20 years ago, from very large to quite small, and use them all every summer

I do keep an eye open for interesting pots, and at a garage sale found a pair of large Chinese blue and white fishbowl planters. I also look to see what I can find online at reasonable prices, and a few months ago Pottery Barn Canada online had their large Brittany cast stone planter on clearance for $42.16 CAN each. I bought two.

Big pots are just expensive, especially terra cotta. We found a manufacturer that does really nice fiberglass pots, and that lets us get the look we want for much less than terra cotta or concrete.

Even the cheap plastic ones are outrageously expensive now. But sometimes Big Lots has some halfway decent ceramic ones at a better price than in other places.

I've been scouring stores for plant pots the last couple of weeks, too. I found a few pretty ceramic ones at Home Depot and Lowes. They were $40-$60 depending on size. Yesterday I went to At Home; they currently have all their pots Buy One, Get One 50% off. They have tons of ceramic, some plastic or fiberglass, and a few concrete ones. That sale has been going on for at least a week already, so it could be over any time. I have on occasion found nice ones at Home Goods.

I went to At Home the other day and their prices are moderate but with the buy one get one half off sale, it's a good deal as long as you want two. They have an extensive selection so I had no problem choosing four! It was a lot of fun.

The best price of course is free. I have acquired quite a few free ones or low-low price at garage sales, on Craigslist or the NextDoor website. I have friends who also have good luck with Facebook marketplace.

our Lowes has a plant container recycling spot. Ask, and you can probably pick your pots and take them for free ... tho most will be black..

My Habitat for Humanity's ReStore usually has a good supply at good prices.

The OP is looking for decorative ceramic or concrete containers/planters, not plastic nursery pots. She already indicated she had plenty of those.

I got these heavy blue pots at TJ Maxx a couple weeks ago. The largest was $15. My local nursery sells similar ones for over $50 each. I prefer simpler styles but they did have more decorative versions, too.