Just like Utopia Shard could be the strongest of all the "Shards", Utopia Fragment might as well be the strongest when it comes to "Fragments".
Adding an additional cost before the runner can steal an agenda has been proved as a very powerful mechanic by the NAPD Contract, hated by many runners and loved by many corps (ok, NBN first and foremost!).
If you install an agenda and the advance it twice, you're basically making it a clone of NAPD, telling the runner he'll have to pay 4 credits more (in addition to actually reaching it, that is). Not to mention, it works on NAPD Contract as well, and 8 credits is definitely a lot to pay for just 2 points.
You have some bad publicity? No big deal, keep advancing that NAPD, it'll just make it increasingly expensive to steal, after all.
Mushin No Shin rejoyces too, you can just use it on an agenda and place a single ice in front of it. The price to reach & steal that agenda might already be too much for the runner.
I would say it's a pretty nice ability for a 5/3 Agenda, easily worth a place in my decks. Not that you can have more than one anyway, unfortunately: Limit 1 per deck.!