I think it's silly to buy bags that are made in and shipped from China and call it "green." That's like buying a brand new hybrid car with a battery with a finite lifecycle and no recycleability, when you have a perfectly functonal car in the driveway, and calling that "green." The only "green" is the money given to retailers.
However, I do have a stash of bags that I have been given at various events and seminars that I will re-use for shopping. I also have a large stash of plastic grocery bags (my DH is horrible about bringing them to the store whenever he goes) in the broom closet. Those also get used and re-used.