I've recently started selling a lot of small anime goods such as rubber straps, can badges, and keychains. I've been shipping these via USPS First Class which on average costs me $3.10-$3.50. I sell on eBay and purchase my labels through eBay. Recently I learned it would be cheaper for me to ship some of these items as Flats, which they easily fall under the criteria for. It would be at least 40% cheaper than when I ship via First Class, even including the fee for adding tracking. Problem is, eBay doesn't have an option to purchase labels for Flats even though my package meets the full criteria. Is there a website I could use that would allow me to ship via this service, while also obtaining a tracking number?
I'm no stranger to using other sites to print labels, I often use Pirate Ship to save a few bucks by using Cubic Rate. Seems though that most all the label purchasing services I could find run via costly monthly subscriptions, with Pirate Ship being a anomaly due to it being free. My hope is that there's another free service out there I can use to purchase labels for Flats commercially. Manually going to the post office, manually writing down the address, or using postage stamps are not an option. Tracking is a must. Thanks for any advice on the topic.