Frankatron

Simple question, if I'm creating a character with rank 3 Blacksmithing, can I craft and modify my own starting gear? I imagine my character has been working for a long time in order to learn this crafting skill. I think it's fair to assume he's created a few items for himself. However, the true question is one of starting character balance. The counter point is that I've spent my valuable "3" in a crafting skill so as to gain this benefit and it plays well into my Tinkerer's background. I'm pretty sure most FM would say no.

I'm trying to create a tinkerer. I have an artefacting rank of 3 and starting scripts of $10. As a tinkerer I get Darlin magical theory. The books says: This means I need at least $15 scripts to create my focus, which is $5 more than I start with and I still need to purchase some starting gear. Does that mean I can't cast spells until I can afford to create a focus? That seems a bit unfair.