The target market is very, very large. That bodes well for prices, since the costs of R&D and red tape can be amortized across a huge number of people and long spans of time.
The most likely form of longevity assurance technologies will be infusions. Think about the cost of, say, TNF inhibitors today. It is a mass-produced biologic that a bored technician runs into you through an IV, and is $5-8K per procedure last time I looked.
The really expensive medicine today is either experimental (new technologies still in development) or requires the attention of a lot of highly trained staff for some time (surgeries, chemotherapies).
But the mature longevity assurance technologies of tomorrow will not be individualized, since everyone ages due to the same root causes. They will be mass produced infusions of nanoparticles, gene therapy vectors, drugs to break down metabolic byproducts, that sort of thing. Factories will make them in bulk, and clinical assistants will inject a program of these things into individual patients once every ten to twenty years. Since everyone will benefit, the individual cost will drop with the massive scale of sales and delivery.
