It could be very important for you to ensure that the building & plumbing person working for you is a licensed professional. It probably does not help a to cut corners on quality of work in order to attempt to save a little money. A good price can sometimes ensure a good outcome.
The rules will like vary in different locations, however, a licensed worker is usually always recommended as the standard. People who want to officially call themselves skilled workers usually need to go through a period of apprenticeship. The worker will then likely need to be given credence by the person who trained them and, in addition, obtain insurance before they can be begin to market themselves as a professional.
It is usually a big responsibility to be a service professional. When customers are paying someone to do a job for them they may likely have high expectations of the work being done. Customers usually like to get their money's worth.
Sometimes, a customer may have more work that needs to be done than they have money to pay for. When someone tries to get more work out of a worker than they should that is probably when quality begins to slip. A customer might even consider giving the work to someone who is lacking proof that they are fully qualified.
However, in the long run a customer may end up unsatisfied. It might be true that a person may get what they pay for. Paying for work that may be shoddy could mean having to do the whole project over again.
Sometimes, it might be best to section work off to a professional building & plumbing personnel rather than skimp on quality. A client could likely get part of a job done now and save up to get more of the work done at another time. In a case like this, probably, paying for the cost of a licensed worker will normally save you more money in the long run.