The others gave you excellent advice. All you can do is ask. Some banks will sell bags from the machine, some won't. Of those that will sell, most require the bag to be full. Rarely (but it does happen) you will find a bank that will just simply pull the bag and sell it to you on the spot.
Although through experience, I have learned one little trick that will occasionally work. When a teller informs you that the bag cannot be purchased, either ask the teller to check with the manager to make sure, or better yet ask to speak to the manager yourself. Sometimes the teller is mistaken. Sometimes the teller just assumes the answer is "no" when in reality it isn't. Its worked for me a few times. In many of those instances I was the first person at that bank ever to inquire about buying bags. Usually the holdup (if there is one) is that the bank assumes that you will just buy the bag, search it, and dump it right back into their machine. If you can alleviate those fears, you have a decent chance of scoring the bag.
Numismaniac said:
No secret tricks. I just ask. Sometimes they are willing and sometimes not. If I get a vault teller from another branch of the same bank, I usually tell other branches that "What's her name at branch over on Main Street sells me bags off their machine..." That actually usually works. However, you just have to ask. I've noticed banks are more willing to do it here in the central/south US than on the East coast in my experience...
Good luck!
I have done this before, and it has worked a couple of times. However, I no longer do this and advise against it. Here is why: While on a road trip I had just bought a bag from a particular branch. A few miles down the road, I happen upon another branch of the same bank. I ask the teller about buying the bag and I'm told that it is against company policy. I inform the teller that I just bought one from one of their other branches. He gets on the phone and calls the manager. She shows up and I repeat my request. Again I am told that it is against company policy to do that. Again I state that I had purchased a bag from another branch. Her face instantly turns red and deepens into a scowl. She says something like, "Oh really? Which one of
my managers allowed you to buy a bag from the machine??" I instantly realized 2 things: 1. I am talking to "the" manager, not just "a" manager. 2. The nice manager down the street that just sold me a bag did so against company policy, and very well might get into trouble over it. Not wanting that, especially after her violating a company policy to do me a favor, I quickly told "the" manager a flat-out lie. I told her that
I was lying just to try and get the bag. I excused myself and left. I hope it worked. I have no desire to get someone "written up" or even worse, fired, over a bag of halves.