To find out where your hairline belongs, lift your eyebrows and look to the highest crease in your furrowed brow. Your center hairline should be about a finger breath from the highest crease
The cost of cosmetic surgery differs from doctor to doctor / from clinic to clinic. It is best you see different doctors for consultations. Also consider that cost is not always related to the quality of work or results.
In you case a small incision along the hairline or just behind hairline, 5 cm in length may be all what is needed for correction (shaving with bone bur) of deformity. Although it may be possible to do it endoscopic the location and length of scars (incisions) is similar. I would...