If you want to avoid spending $10-15 or more on shipping, consider investing in a label printer, which you can find on Amazon for around $80 or more. If you're selling clothes, you’ll also need poly mailers, available on Amazon or Etsy.
Using a label printer allows you to ship items for as little as $1 to $3, which can save you money compared to using a shipping kiosk, as you won’t be relying on their supplies.