You can fly to bodrum in Turkiye for £100 person on 3rd may - 15th may from London. You can rent a room/apartment from lemon tree aparthotel via trivago for £110 for that entire duration - this is not all inclusive, however, you could both eat in bodrum/bitez/gumbet for max £15 per day per person and at least you'd get the opportunity to try loads of different restaurants (I personally hate all inclusive food). So far that's £670 and you could budget another £130 for travel (the dolmus is the cheapest and actually very easy way to get around) and the occasional activity like a boat trip. That's £800 for you both which I think is very cheap and it's for 12 days instead of 7

I meant the flight as £100 per person

Also, bodrum was about 30 mins from the airport so not far and not too close either which is good imo. Bodrum city, bitez and gumbet are all fairly close to one another and are easily accessible via a dolmus (minibus)

Lara Beach in Antalya is just 15-20 minutes from the airport. A variety of All Inclusive hotels to choose from. A couple of small shopping areas there or a shuttle from the hotel into the centre of Antalya.
Belek a little further (30-40 minutes) has the luxurious hotels but not much around to be honest.
Side would probably suit you - about 45 minutes transfer and a variety of accommodation. Lovely little town amid the ancient city. Sandy beach.
All from Antalya airport that has year round flights from the UK.