As I wrote on your other comments, it depends on a multitude of factors, especially these:
Size. How large is the map? What are its dimensions (cm/inches/pixels) and desired resolution?
Color or B&W?
Details. What's the level of individual detail you are looking for? This point includes such things like illustrated crests, flags, highly elaborate locations, ornate map borders, etc. As an example, think of the way you'd like to depict a town on your map: you can do it as simple as a dot. But you can also draw, color and fully shade a miniature town.
Style. What kind of style would the you like? I can be flexible, although it’s advisable that it remains at a style that I’m familiar with.
Urgency. How urgently is the map needed?
Sketch. Providing me with a sketch, no matter how simple, really helps me a lot.
License. What kind of rights do you need? Private use, use on a single book, lifetime global use rights, etc. ...
If you like you can describe your projects to me be writing to email@example.com and I'll get back to you asap.