A home run auction is taking shape in the sports collectibles market. The game-used cleats feature Ohtani's rare Kanji signature and artwork of his dog, Decoy. That jacket sale is the latest high-profile auction as more money pours into collectibles — from jackets to sports jerseys to even dinosaur bones. A Tyrannosaurus rex specimen called Gus recently sold at Sotheby's for $50.1 million, becoming the most expensive dinosaur ever sold at auction. Click here for in-depth analysis of the latest stock market news and events moving stock pricesRead the latest financial and business news from Yahoo Finance