Well, I am shipping a renegade to a fellow forum member. It is shipping from PA to SD with the same 'actual shipping' and the shipping cost, priority mail is $24.75 + insurance (Under $30 total). So I would send him and email and copy Gunbroker telling him that he is not living up to his end of the contract and you will not send payment until he takes the package to the post office and gets it weighed and comes back to you with the actual cost of the shipping. Send him your zip code and ask for his. Then you can double check the figures (I'd be conservative and give him the benefit of the doubt and estimate the weight at 10 pounds.)
Just for kicks I went into the USPS web site and calculated shipping from Detroitm MI to Atlanta GA, based on priority mail, shipping a 10 pound package, measuring 40"x10"x3" and came up with a shipping charge of a whopping $15.15. So I would say this guy is trying to give you a snow job.