As investors search for alternative investments that look more attractive than low-yielding bonds or expensive equities, interest in collectibles (art, wine, classic cars) has gathered momentum. Some collectors luck into windfalls, and if you believe collectible indexes the annualized returns leave normal asset classes in the dust. But once you dig into the details, it’s hard to justify collectibles as anything more than an expensive hobby with the occasional upside. “It is easy to understand the superficial appeal of investing in collectables, either directly or through some sort of pooled funds,” says a recent white paper from Barnett Ravenscroft Wealth…