I was charged and paid the cost of the winning bid and the shipping

I bought a ralph lauren bedding set on ebay. As always I factored in the cost of shipping to determine my limit, which was 10.99 (s/h).

I was charged and paid the cost of the winning bid and the shipping. I wondered how shipping would only be 10.99 for an entire queen set with comforter and 4 pillow shams.I did get a really good price on this item but again I factored in the cost of shipping as advertised when I bid.

What would YOU do? I am so freaking undecided. Really, I have no idea what is ethically right for me. I hate to think of this person having to pay an addition $15 for shipping but at same time it’s her mistake and I counted on her auction information being accurate.