Under $100, must be micro-atx, must also be available on http://www.pccasegear.com/index.php?main_page=index
Get the ASUS M5A78L-M LX V2. I am also a PCCG buyer and I always buy the ASUS or Gigabyte boards. I sometimes go ASRock if I'm doing low grade server, storage, budget or Bitcoin work!
No mATX support 6300 unless you can get lucky with one that has the newest bios on it (if it supports it at all) I was just looking last week for my own 6300 in my 2nd pc. I gave up because I don't have a 4100 to drop in it if the mobo doesn't come with the newest bios.
Only has 3+1 Power Phase VRM, will work but no OCing at all.