Is 20,000$ reasonable for revision rhinoplasty? 3 hours surgery estimated.

Following rhinoplasty there is normal physical swelling and healing that must take place. Often there is also some emotional stress and psychological adjustment that can take time to reconcile. It is almost always wise to allow for time to pass and allow both physical healing and psychological adjustments to occur. No results are really ever 100% perfect and often, patients become more comfortable with their nasal appearance with time and also trying to focus on other non-nasal issues.  Costs of revision surgery vary. Sometimes costs seem excessive. There is no disadvantage to waiting, and often this is the much less expensive option. 

A revision rhinoplasty procedure should not be contemplated for at least one year after the initial procedure. Once the final healing has occurred, consider another rhinoplasty procedure. It's important have very specific goals in mind on what you're trying to accomplish. Digital computer imaging is helpful to understand what can and cannot be accomplished with the procedure. The cost of a rhinoplasty procedure is directly determined by the amount of time it takes to perform the procedure in an operating room, time monitored under anesthesia by a physician anesthesiologist, and the surgeon's professional fees for performing the procedure in addition to all the post operative follow-up appointments. For more information, many examples, and our current price list, please see the link and the video below

Each surgeon is different, and therefore have different fees.  Some might charge less, and some might charge more. You have to go with the person you feel will do the best job.