When you expect a highly successful plastic surgery operation, you need to hire a competent plastic surgeon. And a skilled surgeon charges more.
Though this is not always true in all cases (there might be great plastic surgeons who are charging less than their worth) most people agree that this is generally the expectation.
The key when deciding on a cosmetic procedure and a surgeon is obviously to do the best research you can. If you really dig into the results from affordable plastic surgeons who offer cut-rate prices, most inexpensive cosmetic surgeries give lesser quality results.