All a smith needs is coal, steel or iron, wind, and water. The only tool he would have a hard time building himself would be the anvil, those are usually cast. The forge isn't all that hard to construct (maybe the fan or bellows) and all the other tools are trivial to make.
The only real cost is steel and fuel unless you have your own mine.
I took a blacksmithing workshop in college and one of the things the 74 year old instructor stressed most was that a blacksmith who doesn't make his own tools isn't much of a blacksmith. He taught us how to make all sorts of tools.
Who makes hammers and tongs? The blacksmith. Who writes compilers? Programmers. Maybe I'm getting old but a programmer who can't write a compiler or interpreter isn't much of a programmer (I wrote an interpreter once, years ago).