You make it sound like the surgery is the expensive bit, but as you pointed out, the implant is very basic electronics. The medical procedure is certainly expensive, but the processors are the truly expensive physical product.
Sound processors are around NZD7-8k a pop and have an expected replacement cycle of 5-7 years.
* Rough guess based on the price of regular, high-end "in-the-ear-canal" hearing aids.
This guess completely missed the point. Cochlear implants are not audio amplifiers like hearing aids are. They must convert sound into electrical impulses which are sent more or less directly at the user's sense organ, via a relatively dumb implant. Now, on the one hand you could say, "yeah well that's just a Fourier transform" but that would also miss the point. A cochlear implant only creates impulses at a limited discrete set of points, and the way those points map to frequencies is not going to obey a nice consistent function. This means the processor must be programmable to adjust the mapping of desired frequency (which may not be the input frequency) to electrodes, which already puts us into needing a rather fancier microprocessor than a hearing aid needs.
Moreover, the limited set of frequencies causes a massive loss of signal-to-noise ratio. The processor has to compensate for this intelligently filtering the sound to make the result useful. For example, it may need to detect and filter background noise. It is not really even attempting to replicate natural hearing because that's impossible; it may be more helpful to think of it hijacking the user's aural sense to do something almost totally different with it, but staying just close enough to natural hearing that the brain has a fighting chance of making sense of the inputs.
This seems like something that ought to have a reasonable social venture develop an open source model with a very long lifecycle and good repairability.
* you undergo a VERY expensive surgery.
* in the surgery you get installed the actual cochlear implant.
* the implant itself is VERY basic and is designed to work with future models of the hearing aid (the one behind the ear).
It is therefore, unlike what the article seems to suggest at first glance, not the case that families spend money (a lot of it - upwards $50,000 per ear iirc), only to be told later that they have to go through it all again. I bet what this family experience is a sales department telling them the very real situation that hearing aids - just like smart phones - improve over time and that old models reach an end of life date eventually. There's nothing new here although hearing aids are arguable much more expensive than smartphones - not that they had to be, Hearing Care Professionals make a lot of money per hearing aid.
But that's a story for another time.