Anyway, a quick googling of "mikor érik" (when is ripe) got me to this page: http://www.hazipatika.com/topics/zoldseg_gyumolcs/seasonality (warning, not in english)

although it doesn't list strawberries. for july, it says: sweet cherries, gooseberries, black currant, watermelon, sour cherry, peach, currant, apricot, plum. the ones that are in the middle of their season will be cheapest. the ones just starting or just ending will be expensive. so my bet is that sour cherry is cheapest.

for vegetables: zucchini (meh), kohlrabi, lentils, sunflowers, capsicum (bell pepper), tomato, pattypan squash, pumpkin, green peas, and horseradish.

If I can figure out what's wrong with the fridge (and whether it has an easy solution), I could make cherry soup http://www.chew.hu/meggyleves.html (recipe in English)

i dont know if they have vanila sugar where you are, but it's equivalent to a tsp or tbsp (but definitely not a cup) of a vanilla i think. you could just keep adding small amounts of it until it tastes good. :)

on the veggies list, the only things on that list that i've cooked with before and would know how to make something edible are: lentils, tomato and capsicum (Both of whom are just starting their season and arent at their cheapest yet)

but there may be other fruits and vegetables not on this list.