Alaska Grow Bucket. I rounded up everything except the grommets (which I will be ordering soonish from Amazon, I think), and made my first attempt. I'm pleased with it, and it only took about five minutes to make. One bucket, one grocery bag, and one colander (hidden in the bottom of the bucket under the bag) and tah dah, you have a self-watering container large enough for peppers and tomatoes.
five gallon bucket on sale for $2
cheap reusable grocery sack $1
small plastic colander $1
Total cost: $4 for a large DIY self-watering container.
I already had the drill bit but that would've been about $4 if I needed to buy it. And if you add in the t-connector which will fit in the bottom hole ($3) and the grommet ($1), you really can make one of these for about $12 or less. Of course, I need to figure out the flow regulator bucket and the DIY rain barrel water butt, but I am pretty happy so far with both the cost and the simplicity of making these. I have visions of bountiful pepper harvests this summer...