And here's the story about onions:
|Canadian Onions on the left, US Onions on the right.|
The US onions go for $2.99 for a 10 Lb bag, and the Canadian onions, such as Onio and Vegco, go for $4.99 for 10 lb. It all varies a bit the the seasons. I've seen the Canadians for as little as $3.99 and sometimes more than $4.99 too. The US onions I've seen as low as $ 1.99 at times.
In short, with $20 or less, you can have 10 lbs of high quality rice and 10 lbs of quality onions, then you can add various lentils, chick peas and beans, and that is most of what you need for staples for the month and you only need to add fresh fruit and vegetables.