I would guess that by the time Twain released Joan of Arc that he had no money worries at all.

By the way - I've heard that visitors to McMurtrys book store in Archer City Texas can find him working there and stocking the shelves from time to time. But we WON'T talk about his work or sign his books for customers. He's said to be a bit of a grump. But with the money he's made I guess he qualifies as an "eccentric".