Hi Topsey,
I am about to book again and I booked flights at this time last year with Monarch through Avro. I have come up with the same price as you, £259 and this is about £40 more than last year. I watched the Monarch prices for this year and if I now booked the same flight for September it would be about £300 each
I do like the times on the Monarch flights, 6.30 am departure and 12.45pm departure from Corfu. The Easyjet flights are cheaper but the flight times are not as practical. If I flew with Easyjet this September it would have to be from Bristol which would incur travel costs and the cost would be about £280 each. I know that if I had booked the Easyjet flights months ago they would be much cheaper.
The downside on this would be the return time at 21.45 pm. I really dislike having to wait nearly all day for a flight home, but this depends on your accommodation. In a villa like Eileens you could treat the departure day as a normal day, but if you were in a hotel and hade to vacate your room by say 11.00am, you would have a long wait without the comfort of your room.
I, would always pay extra to go with Monarch, because the flight is an important part of the holiday and we even pay extra for more leg room to give is more comfort. I think it depends on how many times you go to Arillas in a year, and that would make a big difference in wanting to get the cheapest flights. You pay your pennies and take your pick I suppose.