Are you shipping LCL or by 20' unit?
LCL charges either by m3 or weight, depending how heavy is the weight.
For electronic stuff, better to get insurance. Cost dependant on your invoice.
Come to Sg, need to pay port tax too. If I did not remember wrongly, should be a few hundred and not forgetting 5% gst if the item is for local use.
So.... my best advice to you is to get a freight forwarder cos it is very headache thingy la.