Different type of value, the ones I'm talking about are valuable because of the potential information to learn from them, not because they themselves are as storied. Yes, Kusanagi no Tsurugi and the sword of Goujian are incredible, however the ulfberht gives clear signs of the vikings trading with India and China in around 700 ad. This information is the value of the ulfberht swords, while kusanagi hasn't been seen, and can't be studied, so nothing can be learned from it. The sword of goujian is truly the pinnacle of swordsmithing with the technology from its time, but ulfberhts and this sword are beyond their time.
You're arguing about the difference between an artefact with intrinsic value versus one whose value is based on what information we can glean from its very existence. Of the two, I'd say that the former is a bigger deal because we attribute greater importance on artefacts from famous people than those from non-famous people. In addition, I'm not sure what the big deal is that the Vikings had some contact with India or China in 700 AD. We already knew that they were prolific traders, and that one of their big trading partners was Constantinople. Constantinople in turn had tons of contact with India and a bit with China. The addition of the Vikings to this doesn't come as a much of a surprise, and unless there was sustained contact, it probably isn't that significant.