I bought a bumper from HTguy. It looked like he made the box from a few boxes. Can't remember how much the shipping was. That depends on how far it's going.

 

greyhound is the cheapest, but then the person has to pick it up at the nearest station. should be around $30-$40.

just bubble wrap the hell out of it and take it to ups, fedex or dhl. you dont need a box for UPS i know. i shipped a integra type r spoiler and just wrapped it in a lot of bubble wrap. they took it with no problem.

also if the person lives kinda close to you, you can use USPS. I recieved a bumper in about 5 days using USPS and it was just bubble wrapped. the guy lived about 8 hrs away from me. the cost was like $30.

 

Go Greyhound.....wrap the crap out of it with bubble wrap. I had a bumper shipped from across the country for about $50 that way. You drop it off and the buyer goes to his nearest greyhound bus stop.