The shipping charages seem OK. I've seen better, however I've also seen worse.
Generally, one can gather if a person is trying to make all their money on shipping, or a small amount.
Many people factor "Handling" into the shipping. Handling can be the cost of the shipping box/envelope, packign material, the drive to the post office, and the time it takes to do all that.
Many times when I've sold on ebay, I've takced on another $1-$3 to cover fuel, time and packing materials.