I do that also, on books and DVD's from amazon.com, you can save alot of money if you buy frequently. I usually try to combine my purchases also. After a certain amount you pay no shipping, plus no sales tax. It rocks!
RE: Store in BC leaks 15 copies of the latest Harry Potter b
If you have children who've read all the Harry Potter books and want something else good to read,try some of the Lemony Snickett books[my grandkids love that series,too.]