Cheap Ass Shipping Supplies?

So aside from the general dollar store for bubble mailers, and any big box or medium box store for boxes to cut up (Like Walgreens/Walmart/Lowes item display boxes), anyone know of a good source for cheap supplies?

Ebay auctions, either buy it now or regular auctions for bubble/padded mailers end up being the same as, or more expensive than, the local dollar store. 5 #0 mailers for $1 is the same as the going rate for 100 #0 mailers for $20 :/ There should be a source cheaper than 20 cents a mailer.

Amazon has the zero mailers you mention for 13.6 cents each if you buy 250.

http://www.amazon.com/6-5x10-BUBBLE-MAILER-PADDED-ENVELOPES-250/dp/B001M544EK/

I personally go with these monsters for the 26 cents; I like 'em because they work with most strategy guides or an order of three games or so:

http://www.amazon.com/gp/product/B000GHZZV6/

Yeah I just bought a big box of #5's from Amazon, was the best price I could find. I mostly use them for selling books.