I wanna say I charge like 7k for T1 topaz, but I do forge them with higher end specs (lvl 8 or higher speed) so brews are not really needed.
As for the T6 diamond hammers, usually charge about 10k, with lvl 9 speed.
But honestly, its really about consistency. People will pay a little more, to go where they KNOW they will always be in stock at.
Also, put a price on your tools that makes sense to YOU! Because what most people do not realize is, how much mental strain it is forging non-stop!
Hope this helps <3