I see clients from all walks of life and all ages. Everyone has 'their' normal.  In one perspective, it's sad that there is such a thing as 'normal'.  Eyebrows, in a funny kind of way, is a fashion statement. They frame the face. But what if you do not have eyebrows. You feel very self-concious, not 'normal'.  Being a para-medical tattoo artist, I give people eyebrows tattooed in tiny, tiny hairstrokes using different colors of ink. Now, if you are over the age of 18, you can have this procedure done. But what if you are young, in school and you have no eyebrows.  In certain states, it's against the law to tattoo any one under the age of 18, with or without parent / doctor consent.   In my state, I'm in the process of having a bill passed in order to perform tattoo procedures: eyebrows, cleft lip, on clients under age 18 with parents and doctors consent. A young person should not have to go thru school without feeling 'their normal'. 
These procedures are very expensive no matter your age. I have a non-profit organization dedicated to para-medical tattooing.   I would love for every person in the world to feel 'their normal'.