[techo]

I got one for my emergency rain water filter. It's much bigger than it looks in the picture.
It's a great deal for the spigot, prefilter sock & filter. You can't go wrong for the price. I should have ordered several.
I picked up a couple of Encore (food grade) buckets and lids from Walmart. My plan is to use rain water from the roof, filter it and use it for showers, washing dishes & clothes. I have my water barrels filled for drinking water now and I plan to add a real Big Berkey later.
Another member had this link for the Big Berkey up. It's a steal @ $200
http://www.h2ofilters.com/britberbiggr.html

 

[techo]

The stainless in Berky over plastic any day.

I agree for your drinking water you should not skimp and the British Berkefeld can't be beat but, you can set those buckets up outside and collect water for general use. You could also trade off this "drinking water" to people like the OP suggested.
I like these water storage boxes that you could fill up for that purpose.
http://beprepared.com/product.asp_Q_pn_E_KW S100_A_name_E_
There would be folks desperate for clean water if TSHTF.