Can't say anything about the apartments other than they look nice when we've passed them - do Thomson not give you any advice about what's in apartment?
Suncream is more expensive over there (Nivea, Delial, Piz Buin, Ambre Solaire etc) we used to buy over there but now with good deals in supermarkets/Superdruge etc it works out MUCH cheaper buying over here.
Shower gel & toiletries - if you're wanting brand names (Dove, Nivea etc) then you will usually pay more than here.
Stick to the bigger supermarkets - Bip & Syp rather than Spar supermarkets which are usually more expensive again.
When are you going?