Why worry about what razor to use. Just pick one and that's it. No need to get too anal about it. Eventually you will get through your collection-rotation. Don't try too hard at this thing.

As far as robberies go it depends who is doing the robbing. if it's an addict they will take anything even if will only get a few bucks for it and they have the time. if they are strung out they don't know what they are doing anyway.