What are the typical prices and treatment intervals for Botox?

Lately, I've been bothered by wrinkles every time I look in the mirror, so I'm looking into dermatological treatments.
My friend told me that if you stick to the Botox schedule, the effects last a long time.
Since it's my first time, I'm not sure how often I should get Botox to maintain a natural and pretty look.
I am concerned because I heard that the time it takes for Botox to show effect on areas like the jaw or around the eyes can vary from person to person.
I also heard that if you get hit too often, you develop resistance.
I am really curious to know what Botox cycle those of you who have already experienced this usually use for your care.

And, speaking realistically, I would also like to know the price.

I would appreciate your advice.