A friend of mine just introduced me to this site, so I have to say I don't have a ton of information. BUT I am quite excited about its prospects and thought I would share this with all of you.
The website is called ThredUp.com and you can exchange clothes, and only pay shipping. That sounds great to me. There is one thing you have to be invited to the site. So, if you are interested let me know by emailing me at couponqueenholly at gmail dot com and I will send you an invitation to the site. It seems that as long as you are sending out boxes you can request boxes for the sizes you need.