PayPal is the preferred payment method. Combined shipping discount for multiple purchases calculates automatically when items are placed in shopping cart before paying with single payment. US buyers pay $1.00 to cover packaging and 1st Class postage, and pay only $0.25 for each additional patch. Canadian buyers pay $1.25 for first patch and $0.30 each additional. All other international buyers pay $1.50 for first patch and $0.50 each additional. I ship "First Class Mail International" to customers outside the US.