Shipping cost in the US starts at $2.50 for the smallest weight item (choker).. it goes up in increments from there. Shipping cost includes the cost of packages, packaging materials, postage. Items like clothes weigh more so the base shipping price is higher. Items that need larger packages may be priced higher for shipping because of that cost of box or weight.
Shipping cost for international starts at 9$ for the smallest envelope (choker) and goes up by weight from there. Clothing starts at $12 and goes up. Same as US parcels.
If you see less on your parcel stamp than what you paid, it's because I shipped multiples and got a discount or maybe a portion of your cost was added on for packaging or supplies. All of the shipping cost goes to shipping in some way or another.