If it is not worth building it well, then it is not worth building it at all.
As builders we are the ones to repair our work if it is not built correctly the first time. This does not mean over compensating to avoid problems, it means using our skill and experience in selecting proven materials and and using construction techniques that are appropriate to the project. While cost is always a factor, we are charged with balancing initial cost with lifecycle cost. It is never a good idea to spend less now knowing our client will require future expenditures to repair or replace a poorly executed component of the project.