In general, I complete all aspects of the knives I make, whether they are damascus or a single piece of carbon steel.  I complete all of the finishing, heat treating, handle and guard work, and sheaths myself.  

I use a variety of steels for making the blade of the knife.  For Damascus steel, I normally use 1095 Carbon Steel and 15n20 (nickel bearing steel) and the design of the knife will determine the layer count and pattern.  For blades made from a single steel, I normally use 5160, O1 or 1095.

I typically use 416 Stainless for guards and pommels, and various hardwoods for handle material.

Pricing depends on materials and complexity:
Single steel hunter type knives (around 4 inch blade) start at $250
Larger Bowies start at $400
Damascus steel used in knife construction adds to the cost, as well as some choices in handle material.