I tell all my students to not buy more gear until you master what you own. Summer of 2005 I bought a Canon 20D and 24-70 2.8L. Soon after i bought a 70-200 2.8L. These 2 lenses covered almost everything i needed working as a photojournalist. A few years after graduating i bought a 15mm 2.8 Fisheye Lens. To offer rentals to students i also bought cheaper primes: 50mm 1.8II...