It should tell you the price if you look at your booking or do a dummy booking as the prices will/should be displayed there. None of the old CW seats have any extra legroom. The last row has direct aisle access but E seat there is a bassinet seat and will be blocked until maybe about T-72 or at OLCI.

I've never had an issue stepping over but I don't know how able your parents are/can do this but it's not really a high step over really.