I wrote about the amazing low prices at Edgewater Produce earlier on Chicago Metblogs.
Here, a visual representation of what $20 can get you there:
Chocolate covered pretzels - $2.17
Chocolate covered peanuts - $3.35
Sesame sticks - $1.36
5 MacIntosh apples - $1.25
Big box of assorted cookies - $2.00
Fresh blueberries - $1.98
20 small flour tortillas - $1.69
Big hunk of jalapeno cheese - $3.89
10 Senor Freeze popsicles - $.99
Fresh bunch of spinach - $1.98
Broccoli crown - $.36
As a comparison, if you were going to spend $20 on Guinness at your average Chicago pub, you'd probably get two beers.