If they're buying, restoring and selling motorcycles it's more like money shrinking, so your equation is wrong. Buying for $$$$ then selling for $ equals

, and if those frowny faces are attached to blood thirsty madmen....yikes.
I think his collection of racing motorcycles is more a representation of, "I have more money than I know what to do with so what the hell!" Kind of like a fellow I know who has decided he should collect watches. He landed a high paying tech/software sales gig and immediately went out and bought a Porsche Macan. The cranky old purist in me wanted to say, "That's not a Porsche; that's an SUV.", but I restrained myself.