Megabus has really cheap bus fares. On the weekdays they are only $1, $8, or $15 . They say they don't take bikes on their site, but I emailed them and they said it would be ok if it was boxed up. So I can go from Pittsburgh to Cleveland, Toledo, or Chicago for $1. I was thinking about taking the bus to Cleveland and biking back. That would be around 200 miles (a good 3 day trip).

a map of Megabus' bus stops.