I've used it once to deliver a ped from central PA to southwest MI.
It was like 225 bucks.
You have to wait until the perfect bid comes up. The first few are going to be like triple what you want to pay. Have to be flexible about the dates/times also.
The seller didn't palletize it but they did wrap tank in bubble wrap/secure loose parts etc. Was delivered in the back of a pickup.
Overall it was a great experience, but i'm sure it different based on the carrier.
I'd do it again, but only if the shipping doesn't outweigh the cost of the bike itself.