I've always know that badminton is a game of movements.
The requirements of badminton is very different from sports like sprinting or tennis.
badminton shoes need to be tough and able to absorb impacts like sudden stops, change of direction and jumps.
The heels absorb most of impact on lunging. When in the ready position, the balls of feet absorbs the weight and pushes the player forwards, sideways or backwards. Therefore its easy to see there's movenment in 360 degrees.
Therefore, the shoes need to be sturdy enough to handle all this forces. Usually a tough leather upper is sewn by thick threads to renforced the shoe upper.
The center of gravity needs to be low enough, not to cause ankle sprains.
Therefore if possible, don't skimp on cheap shoes, its the tool that helps your game, protect your joints and prevents injury.
This video shows how the impact our feet is subjectd with proper footwork.