This is a basic reality of construction. For construction of a project, you can get two out of the following three, never all three:
Inexpensive * Fast * Good
Inexpensive + Good
This is possible, but at the expense of speed. You will need time to find a contractor who is inexpensive (most likely at the beginning of his career), yet will take the care necessary to build a high quality project.
Inexpensive + Fast
You are most likely to get a contractor who will use the least expensive components assembled with less than meticulous care. Expect cheap versions of the building components. Occasionally, inexpensive items assembled quickly can work out. Expect a lot of “hammer-to-fit” and “paint-to-cover” solutions.
Fast + Good
You will need to hire a very capable contractor who has excellent quality subcontractors and vendors that he has used often. Hope for a break in his schedule where he can fit your project in.
*This entry is half tongue-in-cheek, but often more true than not.