Last time I shipped a gun the cheapest option was USPS via my LGS as some have pointed out above. I had to pay the postage (Priority Mail). I also had to pay for the LGS service, which was $50. I thought that was very high, but it was still cheaper than other options. Since then I found a FFL who will do it for $25 plus postage. So I suggest to the OP to check out more than one FFL.
