I just went to wal-mart to see if they had anything. Well these are online, but a pretty good price. Here is what I copied and pasted.
100 Self Sealing, Zipline Brand Bags, Clear 2 mil. Thick Plastic - 4'' X 6''$3.25 and $2.00 shipping.
That is not bad if that will work?
Most of us could afford that to each just order us a package of these.