So, a little over $5 for the small flat rate priority box,
or over $11 for the medium size flat rate priority box?
"First Class Parcel" is often cheaper, but you have to weigh your own box, and then the price depends on weight. And there is a 13 ounce upper limit on First Class Parcel.
So even a dozen pair of Small thin gloves might be too heavy for First Class Parcel.
And four pairs of the winter gloves would be almost too heavy.