You might consider offering it at a lower shipping rate or even free shipping in order to get more points. It doesn't cost $4.00 to mail a magazine within the U.S.
I realize that envelopes and stamps cost money -- but Listia is intended as more of a bartering site. You will find that most of the members either offer free shipping or give bidders a break on the shipping. By doing that, you'll find people will bid a lot more points for your items.