I think the closest they have to a competitor is oneweb, which hasn't completed the roll out for their first constellation yet. They are surprisingly close though, and could've been able to actually have an operational internet service if it wasn't for a scrapped launch related to the Russian invasion.
I remember thinking they were basically dead, but they have recovered surprisingly well. Though their satellites are more likely to remain in space since they don't deorbit as easily as starlink. Otherwise the "traditional" satellite internet providers don't really even count as actual competitors.
Also, I thought starlink didn't provide customers with IP addresses and that the whole thing was going through a CGNAT and the sats themselves used private internal addresses. Even starlink business users don't get a static IP, just a publically addressable one through DHCP that could in theory change at any time more or less. That means that the premium is most probably due to the added complexity that comes with making some of their network publically addressable rather than having anything to do with IPv4 costs. From what I'm reading they also seem to be working on ipv6 support (soon™), which is hopefully going to make IPv4 pricing matter a lot less for users. Until then they are probably limited by their CGNAT architecture.
I'll look it up since it could've been just some launch date speculation.