low volume online service. If you want to get in Amazon.com, then the cost would be substantially higher. They would take 20-30% of the sales price as commission. If you only sale one or two books at a time, or if the book is written in Chinese, I don't think even a median volume. Plus the shipping, storage and inventory cost. it's pretty hard to make a profit in short time.
If you go to Barns and Nobel or Borders bookstore, follow their instructions how to shelf the inventory and prepare to get paid in 6-9 months. The cost wouldn't be any cheaper.
Man, know your market before make any commitment.