Right now we assume that the Price of the Item includes the taxes ... therefore we haven't added taxes in the end-user bill. We add delivery fee and market fee and calculate the Net-Payable.

But as you say ... if its needed we can add taxes ... in the bill ... and its not so much difficult to integrate that ...

I will be glad to see more contributions to the project ... i believe one of the best advantages of open-source is that people can share and collaborate openly !