At some point we should make a quest of breaking into Galbatorix's treasure room to recover Rider swords(since they [i]almost[/i] can't be made anymore).  It's a difficult thing to do, but it's something we know isn't [i]impossible[/i].  And if we do it before Galby realizes there are a few extra riders around, his attention would likely be elsewhere.  

EDIT: Or else we should find another excuse to acquire some.