Hi,
Free Samples upto the value of Rs.5,000/- are duty free.
Everything else has a duty amount associated with it, even if value is just Re.1/-
For most buyers who want to buy from ebay.com, ebay has launched globaleasybuys which is a fantastic service. You get one single quote including item cost, shipping and customs duty with clearance and works out very cheap.
I just bought one mobile from ebay.com using the global easy buy and it was a good experience. The product arrived in good condition within 10 days or so, customs cleared.
http://orders.ebay.in/ws/eBayISAPI.dll?ImportHubHomePage
Regarding CHA. Most couriers have their own clearing service and small value consignments are cleared by themselves. A CHA is required if you need to file a regular "bill of entry". A Bill of Entry is required if the value of your consignment is high, say above 50,000 inr.
Regards,
Paresh