I sometimes feel guilty asking for the actual cost of sending something to someone. And there are times when I've undercharged for the actual cost.
Although being charged $20 for something that I know I could send for $5.00 - including packaging - really does irritate me.
Sometimes it does come down to - How much do I really want the item?
I agree that sometimes the costs do seem unreasonable. But as others have said, there is usually more involved than just the postage or basic shipping charge.
I prefer to have those costs "buried" in the cost of the merchandise, but it does seem kind of silly when I think about it.
$4.00 for the item + $6.00 for S&H versus $7.00 for the item + $3.00 for S&H