Most people are willing to spend the cheapest amount they can without sacrificing quality unless the brands value is so ingrained that even with better quality if you buy something society will perceive it as inferior quality
Gillette has a strong brand but only because their razors are best quality. They will remain best sellers until that is the case
However if Cadbury’s comes with best chocolates you will still buy Lindt if you have given Lindt before as a present. People receiving Cadbury’s even if you paid more wont appreciate it as much as when you gave them Lindt last time
Likewise for perfumes
You won’t mind switching to topaz blades in a heartbeat if their quality is better than Gillette and price cheap enough that instead of a roce of 40pc on Gillette, topaz makes 20pc
Companies have tried to beat Gillette with strong offers, promotions and free products. But no one has matched their quality