I would note that the powder is only worth something if it is not open. An open can of powder is worth nothing more than the pretty flame it makes when you dump it in a safe area and light it on fire.
I personally would never use and open can of powder to reload from unless I was the one that opened it. Just my thought.
Sorry I can't help you out on the value, I haven't followed the Taurus market, although I do own both Rugers and S&W in .41 magnums.