Repairing existing materials and components is generally more cost-effective than complete replacement for several reasons:

1. Labor Costs - Repairing takes less labor time and costs compared to full removal and replacement. Things like refinishing wood floors, repairing drywall, or reglazing bathtubs require much less labor than tearing out and installing all new materials.

2. Material Costs - When repairing, you only pay for the small parts/materials needed versus buying all new components. For example, reglazing an old tub costs far less than buying a new tub, surround, faucets, etc.

3. Disposal Fees - Avoiding full demolition means minimal disposal fees for hauling away old materials to the landfill or paying fees.

4. Embedded Costs - Many vintage items like hardwood floors, ceramic tile, millwork etc. have embedded costs from the original skilled labor to install them decades ago. Repairing preserves this prior investment.

5. Environmental Impact - Reuse and repair is more environmentally sustainable than sending perfectly reusable items to the landfill needlessly.

The key is appropriately evaluating each component to determine if repair is a viable, long-lasting option compared to its replacement cost. With skilled contractors, many items can be refurbished for 30-50% of the cost of replacing them brand new.