The equivalent for IP addresses to what they offer would be closer to running a BGP router or ISP, or generally contracting with network engineers for your data-center's networking.
If you want to run an ISP or AS, believe me it will cost you a decent chunk of money.
I've been running my own AS for years. You can get an ASN and IPv6 from a RIPE LIR for $200/year or less. Then you need a couple of VPSes that are BGP capable. You can get those for $20 month. Then you can tunnel traffic back to your location with a Wireguard tunnel or whatever you prefer. It's relatively cheap! I also have a legacy IPv4 block I'm routing, which doesn't cost me anything.
I registered this one back in the early 90's, predating the existence of ARIN. No fees only on legacy ones, assuming one has not signed a registration agreement. I assume, at some point, I will be forced into signing an agreement, but it's worked well so far.
If you want to run an ISP or AS, believe me it will cost you a decent chunk of money.