Norma, Lapua, RWS - worth something - perhaps 25% of new unfired brass but not much more.
Most of the rest is pretty much worthless. Personally I would never buy or use 2nd hand brass, unless I was very very sure where it came from. It may say “once fired“ but often brass advertised is range pickups which may be well used.
There has been brass listed in the classifieds - will give you an idea