If I Get Septoplasty Covered by Insurance and Want Rhinoplasty, Will the Price for Rhinoplasty Reduce?

Each practice has his or her own financial policies. Depending on the practice, insurance may offset some of the anesthesia and facility fees so there is a cost savings. However, the intent of insurance coverage is to cover only the actual costs related to the Septoplasty.

Prices for rhinoplasty with or without septoplasty will definitely vary with geographic location and with the level of training of your surgeon.  There are serious advantages both in terms of cost and post-operative healing to combining procedures into a singe surgery.  If you are having trouble breathing or recurrent sinusitis related to a deviated septum, I would STRONGLY recommend that you see a board certified ENT prior to undergoing surgery.  You are correct that insurance will cover the cost of septoplasty (you may require turbinate reduction as well- this will have to be determined on examination) and the anesthesia time associated with the septoplasty and turbinate reduction. The cost of the rhinoplasty and cosmetic operating room and anesthesia fees are the fees that you will need to pay out-of-pocket, and these fees can vary greatly depending upon the subspecialty training of the surgeon you choose and the facility in which they operate.
In terms of healing, it is easier to have a single surgery to recover from than multiple surgeries.

Technically, if you are thinking about having a rhinoplasty, you should definitely wait to do your septum until you do both procedures at the same time.  Properly performed rhinoplasty often requires multiple cartilage grafts to reinforce the new structure for your nose.  The easiest place to obtain these cartilage grafts is from your own septal cartilage.  If you were to go ahead with a septoplasty, and then decide to do your nose in a few years, your surgeon would lose the ability to use your own septal cartilage for these grafts and would have to seek out other sources for cartilage, such as your ear cartilage.  It is definitely best to do both septoplasty and rhinoplasty at the same time.
While cost can vary, in my practice (upper east side of Manhattan), the cost is approximately $4000 surgeon's fee (which is a reduced fee for rhinoplasty, since your insurance will pay a portion of the bill for the septoplasy), and $2,000 to the operating room and anesthesia, for a total of around $6000 out of pocket.  Please bear in mind that this is just an estimate based on the information you provided.

I will end by saying that while cost is a consideration for almost everyone, I counsel my patients that the most important thing in choosing a surgeon, assuming that you are choosing among equally qualified and capable surgeons, is choosing a surgeon who's aesthetic and opinion you trust.  Aesthetic surgery is a little bit science and a little bit art.  Inevitably, your surgeon will need to make decisions for you while you are asleep that will impact your final result, and you need be comfortable that you and your surgeon are on the same page in terms of the goals of surgery and what you consider to be a beautiful result.  I find that pre-operative imaging really helps make sure that me and my patient are indeed on the same page.