Formats and concentration
Does higher concentration mean better perfume
Higher concentration does not automatically mean a better perfume. Quality, personal enjoyment, balance and suitability for your routine cannot be reduced to the amount of fragrance material or the label on a bottle.
A HUME Fragrance buying guide

Define better before comparing
You may want a different scent balance, longer enjoyment or a quieter presence. Those are separate goals and do not necessarily improve together as a label changes.
Compare complete versions
EDT, EDP and parfum interpretations may change their notes as well as concentration. Read the exact products instead of assuming a simple stronger-versus-weaker hierarchy.
Let preference justify the price
The version you repeatedly enjoy is a more useful choice than the highest concentration you can afford. Sampling is especially valuable when the price difference is meaningful.
Try this before you buy
Rank two candidates by enjoyment and intended use before looking at their concentration labels or prices.