PURCHASE AGREEMENT dated as of June 1, 2007 by and among NOVAMED ACQUISITION COMPANY, INC., AND CATARACT AND LASER CENTER PARTNERS, L.L.C., SCOTT BECKER, DOUGLAS J. RAEDY, D.O., GEOFFREY E. CLAPP, D.P.M., JOHN R. TRITTSCHUH, M.D., MARK A. NOFFSINGER,...