I'm a bit of a newbie to touching up paint properly (only experience I have is touching up very small dings on car paint, that haven't started rusting!). I'm calling it practice on my bike so far, thinking if I do mess it up and it looks a bit cack, if I get it blasted/repainted in Winter then I don't need to worry :P
If you can keep us updated on how much it costs, that'd be appreciated!