Unfortunately, the reality is that many churches operate on a shoestring budget and scary cash flow. The preacher knows that expensive repairs could mean he doesn't get paid that week. This creates a strong motivation to use the good-old-boy network. He calls somebody who knows somebody and, as long as it works by Sunday, cost is the only object. Carpenters and brick layers are much more plentiful than electricians and plumbers so you know who does most of the repairs.