Im sure they will be tacking on various 'fees'. The last time I shipped, EVERY one had a lower price option than what he charged me, but he went so fast I couldnt object or question until it was too late. When I let him know, he said "Ive been doing this a long time"

Ive found you should give them the first item, watch how they process it, then the rest- many postal clerks try to charge you for 'non machinable', then toss it in with every other letter they do.