One way to furnish a living room is with modular furniture.
The Paradox
Given That they're of the same size and same quality
Why Is It That the modular (multi-piece) version of a sofa costs almost twice as much as the standard (one-piece) version of a sofa?
Goal
We need to eliminate four answers that explain why modular furniture costs so much more than standard furniture (can't use bigger or better materials).