You can likely use the same power supply if it meets the right specs. Re-use the hard drives, Soundcard, all your cables and case. But yea your looking at a new MB, CPU, Ram, and really should go with a new GPU.

If you were to rebuild the rig I did,

Newegg.com - ASUS M5A97 R2.0 AM3+ AMD 970 SATA 6Gb/s USB 3.0 ATX AMD Motherboard with UEFI BIOS
Newegg.com - AMD FX-8150 Zambezi 3.6GHz Socket AM3+ 125W Eight-Core Desktop Processor FD8150FRGUBOX
Newegg.com - Crucial Ballistix Tactical Tracer 8GB (2 x 4GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800) Desktop Memory (with Orange/Blue Light) Model BLT2KIT4G3D1608DT2TXOB
Newegg.com - EVGA 015-P3-1480-KR GeForce GTX 480 (Fermi) 1536MB 384-bit GDDR5 PCI Express 2.0 x16 HDCP Ready SLI Support Video Card

With out the SSD, OS (its a funny story), ended up using the onboard sound over my dedicated SC, resued my case, powersupply, cables, and UV tubes.

I also needed a DVD tray becasue the MB has no IDE, all SATA.

Anyways it would cost you 544.96 without tax/shipping, and without all the stuff I said I left out.