Your last two posts illustrate part of the problem of this endeavour. Who to sell what to? It depends a lot on what store you are planning to 'work' in. One of the hardware stores in my town does not have 'door alarm' EAS systems, so I would get just about anything I wanted, including dremels, security cameras, and electric drill batteries. The other stores have the EAS so I would go for like saw and sawzall blades, brass/copper items, drill bits, and anything small, expensive, and not tagged.
Yeah, you may think it is beneath you to steal copper fittings, but do you have another way that you can leave your house with nothing but the clothes on your back, and come back less than an hour later with over 100$? If so I want to hear it.