Buy Inexpensive Pots
It is easy to find inexpensive fiberglass pots that resemble concrete, stone or porcelain. The cost will be a lot less than buying the real thing. Plus, they are probably more durable over time, too.
I have found inexpensive large planters in home goods stores such as Marshalls, TJ Maxx and Ross. That's where I've found the most surprising savings.
Thrift stores often have planters. I got these two huge brown flower pots for just $10 at my thrift store.