Like Dain I made to do a bit of searching to get some idea what you were talking about and came up with the same images.

Those are hand drawn and even if I could do that, I'd charge a lot more than 100 USD for that much work, especially if you get the copyright or unrestricted rights to re-use it.

Fortunately, I cheat. I work in Inkscape, a vector graphics program, and apply a bunch of tricks to make it look like a pen and ink drawing where everything was hand drawn, when it's really a collection of lines and symbols. It is possible to tell it's fake by looking closely, particularly at consistency of line widths, symbol repetition, and text, but it's much less work and therefore less expensive.

I'd be willing to do the continent map for 100 USD. City maps aren't really something I've done so I can't help you there; I certainly couldn't pull off anything remotely like the "Valley of Osrund" map