Flying is the best option for those seeking convenience and speed, though one must consider the variable pricing and relatively long duration.
The flight from Kusadasi to Istanbul takes about 300 minutes, with prices ranging from 80 to 350 USD. If you're looking for convenience and speed, this is the recommended option. Be aware of the relatively long flight duration.
For the cheapest option, flying can be economical at 80 USD, but keep in mind that prices can go up to 350 USD.
Flying may be comfortable for families due to its relative convenience, but consider the long flight time.