"Where do I begin. Well.
Firstly, the house is gone but that was the cheapest part of it. There is a passage of underground tunnels beneath it all across the city among other things. As such the cellar is intact. I reckon rebuilding it under Nadarr's name would be best on that note since it appears that somebody most likely burned the place down. However by my rough estimate it would be about 25,000 gold. If everybody was to chip in about 4,000 gold, I reckon we can build a headquarters in this city. Of course it would include whatever you want in it, including your own rooms and places of worship.
Secondly, there is a new Blackstaff mage in Waterdeep. While we could go there for the ring, it also has its own perils. I reckon we know that the ring is more than it appears to be and giving it to Olon wouldn't be the best of ideas. If we run now he will likely hunt us. If we confront him tonight, nothing is known and we put our lives on the line. If we lie or refuse to give him the ring, nobody knows what might happen, except that we will definitely be making an enemy. I personally uphold the choice of confronting him without the ring. Stash it somewhere he it'll be difficult to grab, even if he knows the location.
Thirdly, and I think this is important to you Karl, my homeland, Tarmalune, is in a state of civil war. Innocents are dying by the thousands, noble house against noble house. The reason being that I died. As you can see I'm still alive and well, but they do not know it. The ruler is my father who hasn't taken any action regarding the civil war yet. The houses are fighting for my title of heir because they think I am gone, after having been hunting me for so long, as you saw with the assassins. This is the thing that interests you, Karl. Vampires have openly shown themselves in some of those houses and are killing honest Raven Queen worshippers, as most branch families of my line are. I can't exactly imagine why, considering we worship a single goddess, but I'm not particularly liking it. There's one thing we can do to stop the bloodshed, however. We need to go to Tarmanlune and prove I am alive. The catch is that I'm at... let's say bad terms with my father and might need help to deal with him. We have at most three months to prepare before we need to deal with the situation, and I ask of this as a personal favor. I will compensate you if we succeed if that's what you care for. Yes, Nadarr, that includes a horde of gems."