knowlege about expenses to import from china in india

i'm in business of motorcycle spare parts in india & want to import some products from china. but problem is that i want to know the aprx. costing of products. I know the fob port costing of products but dont have knowlege about additional expenses other then products costing like: commision, shipment fright, import duty etc. If any one kindly describe me about that i'm very gratefull for them. Pls help