Yes the exit rows in Y can be purchased for 50GBP or 75USD per pax.

On the 744's the exit row seat Alpha and Kilo are not charged for because they have restricted leg room due to the slide bussel in the door. Not sure about the airbus aircraft.

You can request Alpha/Kilo an no extra cost.

Bravo/Charlie and Hotel/Juliet may be released at no charge close to departure if they have not be previously sold.

There is no extra charge for exit row seats in W (Premium Economy) although some check-in staff seem confused on this issue!

Bazz