Any recommendation for family holiday to Greek Islands/cheapest/best value ?? No idea where to start x

[Fakeblondie]

We used to go abroad regularly but about 7 years ago my DH developed a genuinly extreme flight phobia.
Since then we have driven every year to Cornwall !
this year im hoping hell address the issue andr i think he might come, but its that long since ive been abroad the first glane in a tavel brochure shocked me ! The prices are very high. We have dd 2 aged 16 ds 1 aged 8 and dd 3 who is now 16 months but will be 2 on 29th June next year. Wed love the hotel to be as near to a beautiful white sandy beach as possible-pref Bed and Breakfast but SC fine if hotel or Villa is good.
Can anyone recommend the best way to go about it as finances are paramount.
All inclusive looks too expensive but i`ve only looked briefly .
Also would i be able to pay a smallish deposit this side of Christmas to potentially secure free child places and then maybe pop into travel agents or whoever each month to pay the balance ?

sand requirment rules out a load of islands straight away.

we've been to:
-kefalonia quite a few years ago which might suit.
-looked at corfu last year and SC too expensive/not good value
-Rhodes - if you ignore thalaraki its nice - along east coast. great villa and much better value than corfu (was 1.5k per week)
-stoupa on mainland. lovely. 2 excellent beaches. mountains. again a few years ago but wasn't the sort of place to change much. too quiet though for 16 year old???
-thasos - lovely beach, though might be a little quiet for a 16 year old..though busier resorts maybe ok

i would look at the mainland if i had a 16 year old as there are some hotels on the peninsulars that look a bit more advanced with more activities. think maybe some of the islands maybe a little too quiet.

we found rhodes to be failry expensive. supermarket shopping wasn't vastly different to here and eating out was a little cheaper but not much. its not the really cheap place it used to be.

Olympic holidays is a good place to look if you want a budget package holiday. They start very cheap, and those holidays tend to be in places where they have a pool, a bar serving English breakfasts, chips, beer and some basic Greek food, so not fab quality but they do the job if you just want some sun.

We went to Greece last year and found it much cheaper to bokk flights and accomodation separately. We went to Mastiharai in Kos, it is a lovely little resort with an amazing beach. We stayed in an apartment, we didn't have our own pool but we could use the one at the hotel across the road.