Replying to [mirna]
At first glance, C&F will look cheaper because the insurance is not included in the unit price that you paid.
However, you will still have to pay for the insurance in your country if you choose C&F.
I suggest that you ask your broker in Sri Lanka how much the insurance will cost (it usually depends on the total value of the shipment). At the same time, ask your supplier in China how much it will cost you if they arrange the insurance at their side and add it on to the unit price, thus, converting from "C&F" to "CIF". You can then compare the cost of insurance in Sri Lanka and China.
From my experience, it is sometimes cheaper to buy "CIF" because major suppliers have "blanket" arrangements with their insurance companies under which all their export shipments are insured. Because of this special arrangement with the insurance company, suppliers are able to avail of preferential rates (due to bulk), which you may never get if you are a small importer.
Either way, the key is to compare costs. Good luck!