A solid foundation. I think you need to balance it a bit, sort out the prestige system to award more interesting awards while maybe reducing how often you prestige. I suggest adding choice in potential upgrades instead of just pay more to upgrade for faster stuff.
An example would be, choose between being better at making daggers, or reduce metal needed for crafting a sword.
I also suggest putting a more strict timer on blacksmith crafting so it slows down the pace. Also have the upgrades decide how well the auto blacksmith creates quality on weapons.