text: While you can send it with stamps, it is better to have it weighed and stamped at the Post Office so you have the postage on one sticker instead of covering half the package in 37-cent increments.  You also pay exactly what the postage costs, nothing more, nothing less.\n\nParcel post is the cheapest method of delivery for what you're sending, but sometimes Priority Mail (2-3 days) costs only slightly more, so it's worth it.  In any case, $1.50 sounds a little low given the weight of most shirts.  If you have a home scale, you can weigh it and type in the information at the Postal Service Web site to see how much it costs.  I'd only use stamps if you're trying to get rid of a bunch of them.