Mate,
Sempron LE Series is off the Shelf now, You may only get an Sempron 140 (AM3 45 Watts TDP) for 1.9k which you can couple with Biostar 6150 Chipset mobo (Do not remember Exact Model No) 2.2K or even better is a Biostar 785 G Chipset for 3.5K which has an ACC Option so if you are lucky you will be able to unlock the sempron 140 to a full feautred Dual Core.
Bye.