FWIW 10 gig cards can be much cheaper than 250€ as long as you’re willing to use SFP+ (I got a used pair of cards with a 10m optical cable for $90 CAD) but 25gig is where it gets stupid.

Even if they do supply a capable router, you will probably want at least a switch since most ISP supplied routers only have a few ports. Plus, it’s not uncommon for an ISP router to deliver their advertised speed over only one port, even if the router has several. At the end of the day, though, if you’re paying for >gigabit you probably want to set up your own firewall with a fancy router so you can properly configure your network.

Crazy that gigabit Ethernet is 25 years old and still the de facto standard. IMO we should all be able to afford 100gig inside our homes, finding the bottleneck inside our machines, not between them. Alas, 10gig is for the enthusiasts, and anything above that is for the elites.