I don't think anyone should buy sick animals from a pet store, no matter how hard it is to walk away. If you have a hard time doing this, then don't go into the stores anymore. Buying the animals just shows them that there is a market for sick animals. I personally also believe that people shouldn't even buy dry goods from the pet stores that have clearly sick animals and won't do anything about it when it is called to their attention (and you should call it to their attention, preferably in a non-confrontational manner, as they very well might not know anything is wrong.) If you don't support how they care for their animals, don't support the store at all. They make most of their money from dry goods anyways.
I don't keep, or really even know, bearded dragons, so I don't know if that animal is in bad shape or not. If it is, I would talk to the manager about your concerns and see if they can/will do anything about it. Also write to corporate about it as well. If they refuse to do anything, sometimes reporting them to whoever licenses pet stores in your area can help. If they receive enough complaints, they might do something about it. Have your friends do the same.
Also keep in mind that some things are set by corporate and cannot be changed by the managers (like certain enclosure elements.) Sometimes they are not much of an issue, and other times they are. Just something to consider since the display enclosures are meant to be temporary (example: for many species, a smaller than recommended enclosure usually isn't an issue for a short period of time, but keeping an animal that requires high humidity and amounts of water in an enclosure with minimal humidity and scarce amounts of water could be pretty bad.)
Gordon, it seems that according to your logic, you should be buying every subsequent sick animal at the pet store. Since you bought the animals that were sick, you allowed them to put more (very possibly sick) animals in their store. Since you have done this, should it not be your responsibility to buy and rehab every sick animal that replaces the ones you bought?