If you buy expensive perfume, you don’t look at it like your are wasting money, because perfume is actually considered sadaqah, for other people.
In other words, if you put on perfume, initially you’ll smell it. But after that you don’t smell it. Whereas when you come up to people they smell it. So really the point of perfume is the other people and for that reason you should buy good scent.
The prophet SAW bought the best scent. Even though he was very frugal in his other matters. In perfume, he actually wore the best perfume.”
(Sheikh Hamza Yusuf)