Does simple mobile charge you for the SIM card?

I have an iPhone 4 with no sim, I want to buy one from simple mobile ( 40 bucks a month ) and I was wondering if the SIM card comes free with the plan? I know that online they charge you 8 dollars but what about in store? Need help.

They charge for the sim… Also they only sell tmobile compatable sim card, discontinued att ones.
so you need a tmobile iphone or an unlocked att one for it to work.