Cheap fresh produce in or near SouthPhx/Laveen area?

[luegar]

I'm about to do one of those juice fasting regimes and would like to find a good/cheaper place to buy my veggies. Nothing fancy: carrots, kale, spinach mostly. Any recommendations? Also I'd like to keep it in the SouthPhx/Laveen area but I wouldn't mind driving a bit if its worth it.

Thanks.

Luegar