I dunno if this helps (probably not) but if you purchase your tickets up to 2 weeks before, it's only about 80 dollars... and if you find someone to go with, you can 'companion fare' it and it's even cheaper...
But don't worry, companion fare doesn't mean you have to be... "COMPANIONS"... Heather and I thought we did, so we walked into the bus station holding hands all affectionately... or was that just the convenience store?? I don't quite remember... hmm...

Kate