What are you upgrading, your entire rig (every single piece, down the bolt) or just your mobo, cpu and gpu?
If just your mobo, cpu and gpu, it's fairly easy to go the intel route in upgrading terms (an i5 3570k being $219, a sapphire 7870 for 219, and the rest of what's left on a good intel mobo).
Let us know what you plan to upgrade.