I hate when they don't specify shipping, you're at their mercy.
Not really. I contact the seller and discuss it and get that settled; BEFORE I bid.
Yeah, really. A fair number of Gunbroker "sellers" keep the shipping amount an open-ended question and use that as a means of making up any perceived shortage on their final sale. It doesn't make a damned bit of difference how much you've "discussed" BEFORE you bid.