Hi Debbie
I've bought from OMC before - you can add things to your cart and go part way through the checkout and see the shopping costs before you finish the checkout.
Buying from overseas is pretty good at the moment as the products are half the cost (or less) than the retail we pay in Oz - even with the shipping costs most still end up at least 25% cheaper (depending on the products that you buy).
Don't forget to also see if there are any coupons available for the store you are shopping at (OMC has regular emails with regular coupons) as this can help offset the cost of shipping.
Feel free to PM me if you have any other questions - I've bought quite a lot from overseas over the years (I'm in Nth Qld).
Tamara