i shipped a bumper to the east coast via greyhound for $50 insured, it took 2 days to get there. was in a big box.
In case anyone is wondering when I went to pick them up the guy at greyhound said that to never ship anything in a garbage bag and he was surprised they showed up in perfect condition.
FedEx Ground is a great trade-off for cost/shipping time. I send complete bicycles all over the US for ~$30.