First class international shipping does involve more "handling" for the seller.
1. Labels can't be printed online, thus seller must take time, gas and labor to travel to the post office, wait in line and pay for shipping in person. Not everyone lives around the corner from a post office so it can conceivably take a bit of travel time and gas to make that trip. (And at $4/gallon, that's not small potatoes.)
2. Free shipping packaging from the post office isn't available for first class international shipping, So seller must buy shipping boxes, bubble mailers, etc. to ship.
Therefore, a bit more of a handling charge added on to the shipping cost isn't unreasonable.