i think £100 to change return date isnt so bad , but it must be changed obviously before that ticket expires, i guess if return fare has gone up the difference will also be to pay, as i found with my previous israel flight that never happened
im not sure i will be able to stay longer. so cheapest option is proberbly best, and i thought to extend visa on arrival just incase i do, as it will save running round trying to get it later,
i checked for cheaper flights but too many changes and much more travel hours and not much cheaper, perhaps klm its self is better to deal with,