that can't be true as rich people are by definition a small minority. why not just give the subsidies directly to the companies
Production of early versions is always more expensive because of the research & development, creation/configuration of the machines, etc, etc but the marginal cost goes down drastically. The numbers work out even better as you can amortize those early costs over a larger and larger production run. This means v2 and later editions are cheaper.
It's text book "economies of scale"
For example, look at prices of flights. Before there was no "first class" everything was first class, now there are cabin options.
While that example is a service, more proliferation of service == wider adaption == increased scale of economies == eventually prices come down for everyone.
Your analogy is more appropriate for space tourism.
This presumes rich people never have good motives and any appearance of morality or civic-mindedness they might show is a self-aggrandizing sham. This seems unlikely.