It doesn't hurt to ask players at these machines if they plan to cash them in .... or if they plan to take them home and save them.

Most times, if they are not collectors, if you offer a buck over face, they would rather sell them to you rather than cash them in at the cage.

If you are somewhat discreet and not draw undue attention to yourself, security will not bother you. If the player, or yourself makes a scene, you may be asked to leave the property for "harrassing" a customer.