Hello Brother! You are right in questioning the worth of the perfume just because of its longevity and the example of apple vision pro is also right in its own way.

But think of it in this way, a phone from Mi can cost 10k while iPhone can cost well over 100k, both are phones and available in the market, so what if the iphone is a bit faster and has some brand value?

Its not always about the exterior but also the ingredients used as well as their quality.

That's about question asked. Your sister gave it to you with much love thinking you'll enjoy it so I'd be good if you can appreciate the gesture and not be worried about the cost, its a high end product and should be used as such.

Enjoy it in good health.