HongyuAmyWomen's African Print Elastic Waist A Line Long Maxi Skirt with Pockets

The sizes small to large are a dollar more than exlarges sizes, why?

I wear a size 12, what size should I order in this skirt?

I wear a us size 3x in pants/skirts-will the xxxl work for me? also, 5'8", so not worried about length. tyia!

Unfortunately i didn't get a belt attached to my skirt. what do i do? i threw the packaging away not realizing.