Does the cost of wrinkle Botox vary depending on the area?

Lately, when I look in the mirror, fine lines on my forehead, between my eyebrows, and around my eyes appear more distinct than before, so I am looking into wrinkle Botox. I am debating whether to treat just one area or multiple areas at once, and I am wondering how much the cost changes if I treat more areas.

Since this is my first time getting wrinkle Botox, I would like to know why there are price differences between clinics. I am curious if the cost varies depending on the type of Botox used or the required dosage, or if prices are calculated separately for different areas like the forehead or glabella. I am also wondering if there is a cost difference if I receive treatments on multiple areas simultaneously compared to getting them done separately.

Also, if I plan to receive wrinkle Botox regularly, I think I need to consider not only the one-time cost but also the timing for follow-up treatments. I would like to know how often these treatments are typically performed. I would also like to inquire if I can receive an estimate of the costs along with confirming the desired areas during the initial consultation.