I suggest looking for a camera that has a lens aperature of f1.8 or better if you intend to make pictures in low light concerts and don't want blurred pictures. Otherwise, you're going to have to wait for the lights to come up to a useable level to get a decent photo. It might not be the easiest thing to find since most point and shoots are not likely to have that fast of a lens.
You might look at the Canon refurbs to see what they have. There is a one year factory warranty and usually the prices are good.