Welcome to Nikonians! The Nikkor 50mm f/1.4G AF-S and the Sigma 50mm f/1.4 HSM are your only choices that will AF when mounted on your D3000. The problem is both of theses lenses are well over $400.00. If you can live with a 35mm prime, the Nikkor 35mm f/1.8G AF-S ($199.95) will AF on a D3000 body. It is a little wider, but a lot cheaper alternative. Good Luck and Enjoy your Nikons!