I have no direct experience with Abit boards. That said, judging from the stats alone, you have a different audio chipset and perhaps a different LAN chipset. Just at a glance from the pictures, the Fatal1ty board has two rather large fans (with the OTES technology label) and a chipset fan, while the cheaper board has a heatpipe.
Notice the final stats on the Fatal1ty board list a number of different features that aren't listed on the other board (although I gather from the reviews of the cheaper board that the uguru OC'ing thing is on both).
I'm relatively new to this too, but take some advice from me: don't just ask what the difference is, check the stats and compare the pics first. You'll be surprised what you can figure out on your own. (Don't be afraid to ask, though.)