It is pricey due to the ease of breakage...it would be cheaper to send it by ground freight vice UPS or USPS. The best way to ship is to crate the tank, build a wood box around it, and pad it extremely well, then ship.
Depending on the distance, you might want to contact a regular moving company. If they have a shipment of household goods going out for someone else to the same area, they may take the tanks as well, again, as long as they are crated. Obviously you would have to pay for the tanks yourself.
I was in the military and got very familiar with how these moving companies ship tanks
My 75 went from Louisiana, to Virginia than Virginia to Maryland without a chip....although, the movers from Louisiana to Virginia did break the glass cover.