i have already integrated my site www.ebay.globaltaxgurur.in to ebay and amazon.It is working fine with ebay.you can enter any product ,it will fetch value and shipping cost from ebay then it will ask you other detail to show rate of duty, total duty amount, landing cost,what is duty saving if imported through Post,Courier,Baggage,sea cargo and air cargo.Further duty variability as per purpose such as gift,personal use, commercial use, repair, return.Our Indian tax system is complex and require lot of effort to make it easy to understand for common man.
pl explore my site which is still under development and send me your feedback.
Regards
Ravindra Kumar