Shipping is a flat rate, calculated based on location and overall price. Orders of $40+ will have a slightly higher shipping cost, as they're more likely to fall into the heavier shipping tier.
US: $3, $5
Canada/Mexico: $15, $20
Australia/NZ: $18, $25
International (Other): $15, $20
A NOTE ON SIGNED PRINTS
If you want signed prints, semi-gloss or matte finish is ideal. I haven't yet found a marker that binds well to gloss, which means that the signature can rub off in shipping.