We made the decision early on, not to offer drop shipping to our retailers. This decision was made for multiple reasons, one being that I was so new to the business and really didn't fully understand the costing. If you are a entrepreneur fairly new to the business and in the decision making process, I thought you may find this information helpful. I only wish I would have discovered something of this detail when starting RuffleButts!! I also give major props to Lisa Otto from Boutique Up! Daily for writing such a fabulously informative guide.
You can go directly to their blog to download the free ebook, How To Drop Ship Your Product. Be sure to take advantage of this today, as I think it is only a 1-day thing. I'm sure if you browse around a bit, you'll find a ton of other very useful information. Hope this helps! Sell, sell, sell =)