Farcaster type Technology

I have been reading the Hyperion series lately and I thought it would be pretty cool for a late game tech kind of like the Farcaster. You can build an exorbitantly expensive Farcaster portal on any world and you get instantaneous travel between those systems that have it. 

What I am not sure is how to balance such a technology. It would give an unfair advantage. Suggestions?

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After playing a few games. namely the last one where I was lumeris, quite peaceful. But then all the sudden United Empire declares war on me. His borders are like 13 turns away from me through 2 other factions that I am cool with.  Some kind of late game teleportation tech would be nice. in general. Like the connected wormholes in ES1.