Retired Wall Street executive Peter Karches bought a Saint Ballado colt for $400,000 at the Thursday session of Fasig-Tipton Kentucky's selected yearling sale in Lexington, Ky. The colt is currently the session's top selling horse.Karches is the retired president and chief operating officer for Morgan Stanley Dean Witter and the recently elected vice chairman for the New York Racing Association. He bought the colt by telephone. The big bay colt is out of the stakes winning mare Goulash (by Mari's Book). The session's top selling filly is a chestnut daughter of Gulch out of Knoosh (by Storm Bird) that was purchased for $300,000 by Tim McMurry of Darby Dan Bloodstock. The filly was bought as a racing prospect for an undisclosed client."We are buying for people who want to race and have some residual value," McMurry said. "She is exactly what we're looking for--a good physical and a good pedigree."The Fasig-Tipton sale ends today.