Just I had some discussion about this with one of my colleague from sales team. According to him there will not be much change.
He explained the scenario as below.
Existing Tax scheme.
consider a product which dealer cost is 1,00,000.
Import Duty - 10%
Import CVD - 14%
Import SAD - 4%
So the total landing cost at dealer premise is : 1,28,000.
Now imagine the dealer sell this product with about 30% margin @ 1,66,400 + 14.5% VAT. So the net cost to buyer is 1,90,528.
According to new GST Scheme
consider the same product which cost is 1,00,000.
Import Duty - 10%
Import CVD - 14% = Rs,14,000.
So the total landing cost at dealer premise is : 1,24,000.
Now imagine the dealer sell the product with about 30% margin @ 1,65,000 + 28% GST So the billing cost to buyer is 2,11,200.
After billing (sales of the product) the dealer can apply and get refund for Rs.14,000 which paid at the time of import as CVD.
So the net cost may be about 5% higher as Naturlover said. But we don't know how many dealers back transfer to buyer which tax refund he will get after billing.