Not true. Jcrew Factory does $5 flat rate, or more frequently offers it free. A prepaid label is also provided with the shipment. And unlike Amazon, these clothes are not add-on or pantry-like items (i.e. need to spend some crazy amount of money to NOT pay for shipping, even with Prime), and won't be last-miled by their crappy service or Lasership.
J Crew charges for return shipping even when they ship out for free, just FYI. I'd consider that more of a problem than Amazon's $25 add-on program (which generally isn't relevant for clothing anyway).