Most cheap tickets have many restrictions.
You are not allowed to rebook your return to UK at all
You can rebook but you need to pay a certain amount
No Refund policy etc.
If you want open ticket with free rebooking, it cost expensive.
But it's worth to undecided like you.
I flew Thru Emirates last year and it cost about £750 return,
But I have first free rebooking so I rebooked my flight.
