Hi Biswas ,
The Import process is different then the normal purchase there are different taxes conditions which needs to be captured in tax accounts. also it include few manual inputs to conditions.
the calculation is quite different in both.So clubbing both may be a tricky job,
Also it will be confusing to user and be user friendly.
In my opinion the motto is only to make purchaser`s work easy. He/she should able to distinguish between different conditions and execute proper steps of process.
thanks
Kunal