Sometimes the shipping is re-calculated before the CC is charged. I have contacted the shops to see if I could get a cheaper shipping if it was something I really wanted. If they would ship cheaper I would buy it, if they wouldn't I told them no thanks.
I also look at the shipping before I hit the 'buy' button. I live in a community with lots of LQS, Jo-Anns, Hobby Lobby, etc where I can probably get it the same price right here when I have added in the shipping and get it right now! I love it when they have 'free shipping'.....