A "Harder" sort of server.

Nexon won't do it.

Why? It's not cost effective.

What's the point of catering to a bunch of users that will make them virtually no income? It's easier to just keep the current servers and make harder content that requires you to cube more. Its sad but true that Nexon will never make the game completely accessable to non-nx users, but it's something you learn to accept I guess.

I think it's pretty clear that Nexon would never do it. As OP says, though, a person can dream

Though it makes me want to think up workarounds... perhaps if they catered to the NX-fashion crowd somehow, to pique their interest in spending more NX on aesthetic items? Or sold one-way world transfers in the CS that could only move you to that server?