They've been consistent with the event schedule lately, so it's likely we'll get a new event next week. Personally, I think you should save your eggs unless you're waaaay behind on demon crystals or something and plan on farming Thursday dailies. Miranda's skill isn't a world beater and she'll never be cheap enough to serve as anti-rush, so even if you plan on using her for a while you can still get away with farming her with natural regen and knocking her down to the normal price for a plat heavy.