Starlink seems to be doing pretty well if they managed to get their terminal production cost under $500. Realistically speaking the terminal cost is the greatest hurdle in getting more customers. Also, if they manage to get the production costs under $300 (that's what Iridium terminal costs now) they can also aggressively gobble up the GEO customer base if they want. After all, if the terminal cost is low enough, nothing prevents them from providing some truly low-cost limited plans that would still be better than what GEO could offer in all metrics (since marginal costs for customers with low bandwidth are minimal).