The ideal neckline is a 90 degree angle on on a side view while in straight forward gaze with a visible jawline (a slightly concave contour just under the sides of the jaw) & no excess hanging skin or fat. The neck should have a smooth surface contour without horizontal skin folds or vertically visible muscle margins. The skin should be supple not stretched tight or hard. That is the goal for whatever cosmetic surgery we perform on a patient's neck. Unfortunately that is about all any 2 surgeons will agree to even though the surgeons are assessing the same things fat/skin excess and muscle laxity. The way to get there will vary dramatically from surgeon to surgeon. Therefore your best option will depend on the physical findings at a face to face examination and who the surgeon is.
The treatment for deviations from this ideal depends on the cause of the deviation. The ideal candidate for liposuction is some who has good skin tone, most of the fat in the neck between the skin & underlying muscle rather than under the platysma muscle of the neck, little or no neck muscle laxity & appropriately
proportioned/prominent jaw bone & chin. The result is less dependent on the amount of fat removed than on how much that fat contributes to the preoperative appearance vs. lax musculature, recessed jaw bone etc.
One good way to tell is to grab the neck skin & fat between your fingers while biting down & gritting your teeth. This tightens the neck muscles & gives the trained eye an idea of muscle laxity, fat location.... However, even the most experienced eye sometimes has trouble with this assessment manuever for example when a lot of neck fat is present or when the muscles are extremely lax.
The treatment for very prominent or lax muscles & very lax skin is a facelift procedure. The name is a bit of a misnomer as the neck is affected more than the face. This allows removal of excess skin & tightening
of the muscles when needed. The surgical approach varies slightly depending on sex, age, other physical factors, etc.. The treatment for recessed jaw bones is dependent on the severity of recession & dental alignment. If the teeth are aligned properly & recession is not great an implant can be placed via an intraoral approach to make the jaw bone &/or chin more prominent. In the process the neck profile assumes more of a 90 degree angle in appropriate candidates. In a minority of patients the neck can be treated by liposuction & surgical tightening of the neck muscle alone. This results in a quicker recovery time with lesser chance of complications than the classical facelift procedure.
Unfortunately the photo you submitted is not sufficient to make the assessments described above. Before broaching the subject of cost you really need to know the status of your current condition and what means are required to rectify it. That means you will have to see a qualified surgeon face to face. Once you know that you move on to pricing and how to safely have the required surgery. Going for price before knowing the other factors is dangerous.