Here are some of the ready-made self-watering containers (sub-irrigated planters, SIPs) that were featured in the following book:
17" Self-Watering Rolling Planter by Gardener's Supply, $45. This planter is very deep:
Self-Watering Patio Planter, $40. This is the size of a large storage bin, less deep than the big planter above.
They even have a special Tomato Success Kit, by Gardener's Supply for $65.
These containers are prices significantly higher than the popular EarthBox and its competitor Grow Box:
The containers above are expensive. You can make your own with 5-gallon buckets. They are available at Walmart, Home Depot and Lowe's ($2.67 to $3.60). Walmart has white, no label containers which should work best from an aesthetic vs. the bright orange or grey containers with the logos of the home improvement stores.
I have bought less expensive SIPs made by Apollo, from Amazon, 12-inch, 6 pack for $45:
5-gallon bucket at Home Depot.